Using an Rj45 to D9 RS232 Adaptor with a laptop to control an RS232 device









up vote
8
down vote

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1












I've got an RJ45 to D9 RS232 Adapter that I want to use to control an RS232 device in the following config:




Laptop RJ45 Ethernet port -> Cat6 patch lead -> D9 RS232 adapter -> RS232 Device




Would the above work ?










share|improve this question



















  • 7




    The RJ45 to DB9 adaptor is almost certainly just connecting pins on the RJ9 connector to connectors on the RJ45 - I've yet to come across any of these devices with any logic in them - and a lot of logic (and configuration) would be required as Ethernet and serial connections are very different.
    – davidgo
    2 days ago






  • 2




    Please provide a photo of your adapter.
    – Criggie
    2 days ago






  • 1




    @Criggie, it's probably the adapter that APC used on their uninterruptible power supplies for years, before they switched to using RJ45-to-USB adapters.
    – Mark
    2 days ago














up vote
8
down vote

favorite
1












I've got an RJ45 to D9 RS232 Adapter that I want to use to control an RS232 device in the following config:




Laptop RJ45 Ethernet port -> Cat6 patch lead -> D9 RS232 adapter -> RS232 Device




Would the above work ?










share|improve this question



















  • 7




    The RJ45 to DB9 adaptor is almost certainly just connecting pins on the RJ9 connector to connectors on the RJ45 - I've yet to come across any of these devices with any logic in them - and a lot of logic (and configuration) would be required as Ethernet and serial connections are very different.
    – davidgo
    2 days ago






  • 2




    Please provide a photo of your adapter.
    – Criggie
    2 days ago






  • 1




    @Criggie, it's probably the adapter that APC used on their uninterruptible power supplies for years, before they switched to using RJ45-to-USB adapters.
    – Mark
    2 days ago












up vote
8
down vote

favorite
1









up vote
8
down vote

favorite
1






1





I've got an RJ45 to D9 RS232 Adapter that I want to use to control an RS232 device in the following config:




Laptop RJ45 Ethernet port -> Cat6 patch lead -> D9 RS232 adapter -> RS232 Device




Would the above work ?










share|improve this question















I've got an RJ45 to D9 RS232 Adapter that I want to use to control an RS232 device in the following config:




Laptop RJ45 Ethernet port -> Cat6 patch lead -> D9 RS232 adapter -> RS232 Device




Would the above work ?







serial rs232






share|improve this question















share|improve this question













share|improve this question




share|improve this question








edited 2 days ago









JakeGould

30.5k1093134




30.5k1093134










asked 2 days ago









sam

1,517133567




1,517133567







  • 7




    The RJ45 to DB9 adaptor is almost certainly just connecting pins on the RJ9 connector to connectors on the RJ45 - I've yet to come across any of these devices with any logic in them - and a lot of logic (and configuration) would be required as Ethernet and serial connections are very different.
    – davidgo
    2 days ago






  • 2




    Please provide a photo of your adapter.
    – Criggie
    2 days ago






  • 1




    @Criggie, it's probably the adapter that APC used on their uninterruptible power supplies for years, before they switched to using RJ45-to-USB adapters.
    – Mark
    2 days ago












  • 7




    The RJ45 to DB9 adaptor is almost certainly just connecting pins on the RJ9 connector to connectors on the RJ45 - I've yet to come across any of these devices with any logic in them - and a lot of logic (and configuration) would be required as Ethernet and serial connections are very different.
    – davidgo
    2 days ago






  • 2




    Please provide a photo of your adapter.
    – Criggie
    2 days ago






  • 1




    @Criggie, it's probably the adapter that APC used on their uninterruptible power supplies for years, before they switched to using RJ45-to-USB adapters.
    – Mark
    2 days ago







7




7




The RJ45 to DB9 adaptor is almost certainly just connecting pins on the RJ9 connector to connectors on the RJ45 - I've yet to come across any of these devices with any logic in them - and a lot of logic (and configuration) would be required as Ethernet and serial connections are very different.
– davidgo
2 days ago




The RJ45 to DB9 adaptor is almost certainly just connecting pins on the RJ9 connector to connectors on the RJ45 - I've yet to come across any of these devices with any logic in them - and a lot of logic (and configuration) would be required as Ethernet and serial connections are very different.
– davidgo
2 days ago




2




2




Please provide a photo of your adapter.
– Criggie
2 days ago




Please provide a photo of your adapter.
– Criggie
2 days ago




1




1




@Criggie, it's probably the adapter that APC used on their uninterruptible power supplies for years, before they switched to using RJ45-to-USB adapters.
– Mark
2 days ago




@Criggie, it's probably the adapter that APC used on their uninterruptible power supplies for years, before they switched to using RJ45-to-USB adapters.
– Mark
2 days ago










4 Answers
4






active

oldest

votes

















up vote
27
down vote



accepted










No. Ethernet ports can't transmit or receive RS-232 signals.



If your laptop has a traditional DB9 RS-232 serial port, use that with the appropriate serial cable. If it doesn't, use a USB to RS-232 serial adapter.






share|improve this answer




















  • "Ethernet ports can't transmit or receive RS-232 signals" -- But there are converters.
    – sawdust
    2 days ago






  • 2




    @sawdust Do you have an example?
    – Michael Hampton
    2 days ago






  • 3




    Any RJ45 to serial cable I have seen was made to plug into a switch/router for control or programming like this.
    – JPhi1618
    2 days ago










  • @MichaelHampton -- there's a link at the end of my answer.
    – sawdust
    2 days ago







  • 3




    @JPhi1618, that's just a pinout adapter, it doesn't help with the differences in physical and logical signalling between Ethernet and a serial port. I suppose the reason the "RJ45" connector is used for serial consoles is that it's smaller than the DE9. That might make e.g. the difference between being able to fit the console connector in the front of a switch, instead of having to place it in the rear. It's a bit confusing that the same connector is used, but they're likely to be easy to source, and anyone can find the plugs to make e.g. a longer serial cable.
    – ilkkachu
    yesterday

















up vote
18
down vote













If you have something like this item, then it is merely a pinout adapter and not a serial/ethernet device.



https://cdn3.volusion.com/uvrp7.f3o9w/v/vspfiles/photos/319016-2.gif?1401188765



You could use one of these on each end of a RJ45 cable to make a serial cable. That serial cable could run through structured cable installed inside a wall or similar, but it cannot run through an ethernet switch or vlan.






share|improve this answer
















  • 2




    I've used these for a long time, and they work reliably even with relatively long cables (10+ meters).
    – Ismael Miguel
    yesterday






  • 3




    The RS-232 standard specifies DB25 connectors. Since DB25 connectors are bigger than most modern connectors and thus somewhat inconvenient, lots of equipment has switched to other connectors including the RJ-45 and DE-9 connectors in your picture. That adapter was likely intended to enable a connection between a server or network equipment with an RJ-45 serial port and another device with a DE-9 serial port.
    – kasperd
    yesterday







  • 4




    @kasperd, If you want to get technical, RS-232 describes the interface between a computer or computer termnial (a.k.a., "Data Terminal Equipment", or "DTE"), and a modem (a.k.a., "Data Communication Equipment", or "DCE"). These days, when we say "RS-232" we ignore almost the entire thing, except for its very lowest level---line coding and framing.
    – Solomon Slow
    yesterday






  • 1




    @SolomonSlow Exactly. My point is there are parts of that standard which are no longer in use today including the form factor of the connector. The depicted adapter is for conversion between two of the connectors which vendors have chosen to use instead of the larger DB25 connector.
    – kasperd
    yesterday

















up vote
8
down vote














I've got an RJ45 to D9 RS232 Adapter that I want to use to control an RS232 device in the following config:




Whether you can accomplish your goal depends on exactly what this "adapter" that you have can do.

There certainly are "serial to Ethernet converters" designed for the connection you proposed:




Laptop RJ45 Ethernet port -> Cat6 patch lead -> D9 RS232 adapter -> RS232 Device




which looks a lot like the product application:
enter image description here.




So what is a serial Ethernet converter used for?



Most commonly it is used for connecting a serial RS232, RS485 or RS422 device such as a serial printer, barcode scanner, scale, GPS, sensor or any other consumer or industrial device with a serial interface, to a computer over a standard LAN network.

The advantage of this is obvious; you will be able to control, monitor and communicate with your serial device remotely from a central computer.






How does a serial Ethernet converter work?



The circuitry inside the converter can convert IP/TCP packets to serial data and also convert serial data to IP/TCP packets, so it works in both directions.
Before you can start using the converter you need to install driver software on your computer. This driver software is also called virtual COM software because it creates a virtual COM port in your computer's Device Manager when the converter is connected to your computer. Virtual COM software is usually included with the converter, at least if you buy from a reputable seller.



Once the virtual COM port has been created by the Serial to Ethernet converter's driver software the COM port will show up in your computer's Device Manager as if it was a standard built-in COM port, however it actually is the COM port in the converter at the other end of the Ethernet.





Images of serial to Ethernet converters








share|improve this answer


















  • 2




    These converters are cool and useful, but I don't think I'd call something that requires its own power supply an 'adapter'. OP could probably use this if his serial device needed to be controlled remotely tho.
    – JPhi1618
    2 days ago






  • 4




    "I don't think I'd call something that requires its own power supply an 'adapter'" -- Anything with a digital IC is going to require power. USB adapters (e.g. the USB to RS-232 serial adapter mentioned in another answer) have the advantage that the USB connection provides the power for the converter chip. Ethernet is a not a bus like USB, so there is no power (unless you have PoE).
    – sawdust
    2 days ago







  • 5




    Isn't this missing the point of the question? The user's laptop ethernet port can not be used to drive a serial connection. Yes it can connect over a LAN to one of these devices, but that's not the question.
    – cpt_fink
    2 days ago






  • 1




    Very true. Maybe I'm in the minority but I've always reserved "adapter" for something that is a truly dumb pin-to-pin connection. Now that you mention it I have seen others use "USB to serial adapter" quite a bit (and for similar products).
    – JPhi1618
    2 days ago






  • 2




    @cpt_fink -- The OP wants to "to control an RS232 device", not "drive a serial connection" (whatever that means) as you claim. The description of the serial Ethernet converter states that "you will be able to control ... your serial device remotely from a ... computer." How is that not a perfect answer to the OP's question?
    – sawdust
    2 days ago


















up vote
4
down vote













The physical signalling, and even more so the logical protocols, used by Ethernet are completely different from those of serial ports, so it's impossible to directly connect a laptop's LAN port to a device's serial port.



However, the same connector is often used for both. I think the usage of an "RJ45" connector for serial console was made popular by Cisco, but network devices from other vendors use the same connector. If you have an adapter with a DE-9 on the other end, and an "RJ45" on the other, it's most likely a Cisco-style console cable. Like this one (image from Wikipedia):



enter image description here



To connect your laptop to a serial port of a device locally, just get a USB serial port adapter. They should be readily available and drivers for the common ones (FT232R and PL2303) can be found for most operating systems.



However, if your use case is to connect to a serial port remotely, as in over the network, then that won't work. You'll need something that connects to the network and talks with the serial port of your device. There are commercially available devices that do just that (terminal servers), but you could solve that with another serial-equipped computer too.






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    4 Answers
    4






    active

    oldest

    votes








    4 Answers
    4






    active

    oldest

    votes









    active

    oldest

    votes






    active

    oldest

    votes








    up vote
    27
    down vote



    accepted










    No. Ethernet ports can't transmit or receive RS-232 signals.



    If your laptop has a traditional DB9 RS-232 serial port, use that with the appropriate serial cable. If it doesn't, use a USB to RS-232 serial adapter.






    share|improve this answer




















    • "Ethernet ports can't transmit or receive RS-232 signals" -- But there are converters.
      – sawdust
      2 days ago






    • 2




      @sawdust Do you have an example?
      – Michael Hampton
      2 days ago






    • 3




      Any RJ45 to serial cable I have seen was made to plug into a switch/router for control or programming like this.
      – JPhi1618
      2 days ago










    • @MichaelHampton -- there's a link at the end of my answer.
      – sawdust
      2 days ago







    • 3




      @JPhi1618, that's just a pinout adapter, it doesn't help with the differences in physical and logical signalling between Ethernet and a serial port. I suppose the reason the "RJ45" connector is used for serial consoles is that it's smaller than the DE9. That might make e.g. the difference between being able to fit the console connector in the front of a switch, instead of having to place it in the rear. It's a bit confusing that the same connector is used, but they're likely to be easy to source, and anyone can find the plugs to make e.g. a longer serial cable.
      – ilkkachu
      yesterday














    up vote
    27
    down vote



    accepted










    No. Ethernet ports can't transmit or receive RS-232 signals.



    If your laptop has a traditional DB9 RS-232 serial port, use that with the appropriate serial cable. If it doesn't, use a USB to RS-232 serial adapter.






    share|improve this answer




















    • "Ethernet ports can't transmit or receive RS-232 signals" -- But there are converters.
      – sawdust
      2 days ago






    • 2




      @sawdust Do you have an example?
      – Michael Hampton
      2 days ago






    • 3




      Any RJ45 to serial cable I have seen was made to plug into a switch/router for control or programming like this.
      – JPhi1618
      2 days ago










    • @MichaelHampton -- there's a link at the end of my answer.
      – sawdust
      2 days ago







    • 3




      @JPhi1618, that's just a pinout adapter, it doesn't help with the differences in physical and logical signalling between Ethernet and a serial port. I suppose the reason the "RJ45" connector is used for serial consoles is that it's smaller than the DE9. That might make e.g. the difference between being able to fit the console connector in the front of a switch, instead of having to place it in the rear. It's a bit confusing that the same connector is used, but they're likely to be easy to source, and anyone can find the plugs to make e.g. a longer serial cable.
      – ilkkachu
      yesterday












    up vote
    27
    down vote



    accepted







    up vote
    27
    down vote



    accepted






    No. Ethernet ports can't transmit or receive RS-232 signals.



    If your laptop has a traditional DB9 RS-232 serial port, use that with the appropriate serial cable. If it doesn't, use a USB to RS-232 serial adapter.






    share|improve this answer












    No. Ethernet ports can't transmit or receive RS-232 signals.



    If your laptop has a traditional DB9 RS-232 serial port, use that with the appropriate serial cable. If it doesn't, use a USB to RS-232 serial adapter.







    share|improve this answer












    share|improve this answer



    share|improve this answer










    answered 2 days ago









    Spiff

    75.7k10116158




    75.7k10116158











    • "Ethernet ports can't transmit or receive RS-232 signals" -- But there are converters.
      – sawdust
      2 days ago






    • 2




      @sawdust Do you have an example?
      – Michael Hampton
      2 days ago






    • 3




      Any RJ45 to serial cable I have seen was made to plug into a switch/router for control or programming like this.
      – JPhi1618
      2 days ago










    • @MichaelHampton -- there's a link at the end of my answer.
      – sawdust
      2 days ago







    • 3




      @JPhi1618, that's just a pinout adapter, it doesn't help with the differences in physical and logical signalling between Ethernet and a serial port. I suppose the reason the "RJ45" connector is used for serial consoles is that it's smaller than the DE9. That might make e.g. the difference between being able to fit the console connector in the front of a switch, instead of having to place it in the rear. It's a bit confusing that the same connector is used, but they're likely to be easy to source, and anyone can find the plugs to make e.g. a longer serial cable.
      – ilkkachu
      yesterday
















    • "Ethernet ports can't transmit or receive RS-232 signals" -- But there are converters.
      – sawdust
      2 days ago






    • 2




      @sawdust Do you have an example?
      – Michael Hampton
      2 days ago






    • 3




      Any RJ45 to serial cable I have seen was made to plug into a switch/router for control or programming like this.
      – JPhi1618
      2 days ago










    • @MichaelHampton -- there's a link at the end of my answer.
      – sawdust
      2 days ago







    • 3




      @JPhi1618, that's just a pinout adapter, it doesn't help with the differences in physical and logical signalling between Ethernet and a serial port. I suppose the reason the "RJ45" connector is used for serial consoles is that it's smaller than the DE9. That might make e.g. the difference between being able to fit the console connector in the front of a switch, instead of having to place it in the rear. It's a bit confusing that the same connector is used, but they're likely to be easy to source, and anyone can find the plugs to make e.g. a longer serial cable.
      – ilkkachu
      yesterday















    "Ethernet ports can't transmit or receive RS-232 signals" -- But there are converters.
    – sawdust
    2 days ago




    "Ethernet ports can't transmit or receive RS-232 signals" -- But there are converters.
    – sawdust
    2 days ago




    2




    2




    @sawdust Do you have an example?
    – Michael Hampton
    2 days ago




    @sawdust Do you have an example?
    – Michael Hampton
    2 days ago




    3




    3




    Any RJ45 to serial cable I have seen was made to plug into a switch/router for control or programming like this.
    – JPhi1618
    2 days ago




    Any RJ45 to serial cable I have seen was made to plug into a switch/router for control or programming like this.
    – JPhi1618
    2 days ago












    @MichaelHampton -- there's a link at the end of my answer.
    – sawdust
    2 days ago





    @MichaelHampton -- there's a link at the end of my answer.
    – sawdust
    2 days ago





    3




    3




    @JPhi1618, that's just a pinout adapter, it doesn't help with the differences in physical and logical signalling between Ethernet and a serial port. I suppose the reason the "RJ45" connector is used for serial consoles is that it's smaller than the DE9. That might make e.g. the difference between being able to fit the console connector in the front of a switch, instead of having to place it in the rear. It's a bit confusing that the same connector is used, but they're likely to be easy to source, and anyone can find the plugs to make e.g. a longer serial cable.
    – ilkkachu
    yesterday




    @JPhi1618, that's just a pinout adapter, it doesn't help with the differences in physical and logical signalling between Ethernet and a serial port. I suppose the reason the "RJ45" connector is used for serial consoles is that it's smaller than the DE9. That might make e.g. the difference between being able to fit the console connector in the front of a switch, instead of having to place it in the rear. It's a bit confusing that the same connector is used, but they're likely to be easy to source, and anyone can find the plugs to make e.g. a longer serial cable.
    – ilkkachu
    yesterday












    up vote
    18
    down vote













    If you have something like this item, then it is merely a pinout adapter and not a serial/ethernet device.



    https://cdn3.volusion.com/uvrp7.f3o9w/v/vspfiles/photos/319016-2.gif?1401188765



    You could use one of these on each end of a RJ45 cable to make a serial cable. That serial cable could run through structured cable installed inside a wall or similar, but it cannot run through an ethernet switch or vlan.






    share|improve this answer
















    • 2




      I've used these for a long time, and they work reliably even with relatively long cables (10+ meters).
      – Ismael Miguel
      yesterday






    • 3




      The RS-232 standard specifies DB25 connectors. Since DB25 connectors are bigger than most modern connectors and thus somewhat inconvenient, lots of equipment has switched to other connectors including the RJ-45 and DE-9 connectors in your picture. That adapter was likely intended to enable a connection between a server or network equipment with an RJ-45 serial port and another device with a DE-9 serial port.
      – kasperd
      yesterday







    • 4




      @kasperd, If you want to get technical, RS-232 describes the interface between a computer or computer termnial (a.k.a., "Data Terminal Equipment", or "DTE"), and a modem (a.k.a., "Data Communication Equipment", or "DCE"). These days, when we say "RS-232" we ignore almost the entire thing, except for its very lowest level---line coding and framing.
      – Solomon Slow
      yesterday






    • 1




      @SolomonSlow Exactly. My point is there are parts of that standard which are no longer in use today including the form factor of the connector. The depicted adapter is for conversion between two of the connectors which vendors have chosen to use instead of the larger DB25 connector.
      – kasperd
      yesterday














    up vote
    18
    down vote













    If you have something like this item, then it is merely a pinout adapter and not a serial/ethernet device.



    https://cdn3.volusion.com/uvrp7.f3o9w/v/vspfiles/photos/319016-2.gif?1401188765



    You could use one of these on each end of a RJ45 cable to make a serial cable. That serial cable could run through structured cable installed inside a wall or similar, but it cannot run through an ethernet switch or vlan.






    share|improve this answer
















    • 2




      I've used these for a long time, and they work reliably even with relatively long cables (10+ meters).
      – Ismael Miguel
      yesterday






    • 3




      The RS-232 standard specifies DB25 connectors. Since DB25 connectors are bigger than most modern connectors and thus somewhat inconvenient, lots of equipment has switched to other connectors including the RJ-45 and DE-9 connectors in your picture. That adapter was likely intended to enable a connection between a server or network equipment with an RJ-45 serial port and another device with a DE-9 serial port.
      – kasperd
      yesterday







    • 4




      @kasperd, If you want to get technical, RS-232 describes the interface between a computer or computer termnial (a.k.a., "Data Terminal Equipment", or "DTE"), and a modem (a.k.a., "Data Communication Equipment", or "DCE"). These days, when we say "RS-232" we ignore almost the entire thing, except for its very lowest level---line coding and framing.
      – Solomon Slow
      yesterday






    • 1




      @SolomonSlow Exactly. My point is there are parts of that standard which are no longer in use today including the form factor of the connector. The depicted adapter is for conversion between two of the connectors which vendors have chosen to use instead of the larger DB25 connector.
      – kasperd
      yesterday












    up vote
    18
    down vote










    up vote
    18
    down vote









    If you have something like this item, then it is merely a pinout adapter and not a serial/ethernet device.



    https://cdn3.volusion.com/uvrp7.f3o9w/v/vspfiles/photos/319016-2.gif?1401188765



    You could use one of these on each end of a RJ45 cable to make a serial cable. That serial cable could run through structured cable installed inside a wall or similar, but it cannot run through an ethernet switch or vlan.






    share|improve this answer












    If you have something like this item, then it is merely a pinout adapter and not a serial/ethernet device.



    https://cdn3.volusion.com/uvrp7.f3o9w/v/vspfiles/photos/319016-2.gif?1401188765



    You could use one of these on each end of a RJ45 cable to make a serial cable. That serial cable could run through structured cable installed inside a wall or similar, but it cannot run through an ethernet switch or vlan.







    share|improve this answer












    share|improve this answer



    share|improve this answer










    answered 2 days ago









    Criggie

    696410




    696410







    • 2




      I've used these for a long time, and they work reliably even with relatively long cables (10+ meters).
      – Ismael Miguel
      yesterday






    • 3




      The RS-232 standard specifies DB25 connectors. Since DB25 connectors are bigger than most modern connectors and thus somewhat inconvenient, lots of equipment has switched to other connectors including the RJ-45 and DE-9 connectors in your picture. That adapter was likely intended to enable a connection between a server or network equipment with an RJ-45 serial port and another device with a DE-9 serial port.
      – kasperd
      yesterday







    • 4




      @kasperd, If you want to get technical, RS-232 describes the interface between a computer or computer termnial (a.k.a., "Data Terminal Equipment", or "DTE"), and a modem (a.k.a., "Data Communication Equipment", or "DCE"). These days, when we say "RS-232" we ignore almost the entire thing, except for its very lowest level---line coding and framing.
      – Solomon Slow
      yesterday






    • 1




      @SolomonSlow Exactly. My point is there are parts of that standard which are no longer in use today including the form factor of the connector. The depicted adapter is for conversion between two of the connectors which vendors have chosen to use instead of the larger DB25 connector.
      – kasperd
      yesterday












    • 2




      I've used these for a long time, and they work reliably even with relatively long cables (10+ meters).
      – Ismael Miguel
      yesterday






    • 3




      The RS-232 standard specifies DB25 connectors. Since DB25 connectors are bigger than most modern connectors and thus somewhat inconvenient, lots of equipment has switched to other connectors including the RJ-45 and DE-9 connectors in your picture. That adapter was likely intended to enable a connection between a server or network equipment with an RJ-45 serial port and another device with a DE-9 serial port.
      – kasperd
      yesterday







    • 4




      @kasperd, If you want to get technical, RS-232 describes the interface between a computer or computer termnial (a.k.a., "Data Terminal Equipment", or "DTE"), and a modem (a.k.a., "Data Communication Equipment", or "DCE"). These days, when we say "RS-232" we ignore almost the entire thing, except for its very lowest level---line coding and framing.
      – Solomon Slow
      yesterday






    • 1




      @SolomonSlow Exactly. My point is there are parts of that standard which are no longer in use today including the form factor of the connector. The depicted adapter is for conversion between two of the connectors which vendors have chosen to use instead of the larger DB25 connector.
      – kasperd
      yesterday







    2




    2




    I've used these for a long time, and they work reliably even with relatively long cables (10+ meters).
    – Ismael Miguel
    yesterday




    I've used these for a long time, and they work reliably even with relatively long cables (10+ meters).
    – Ismael Miguel
    yesterday




    3




    3




    The RS-232 standard specifies DB25 connectors. Since DB25 connectors are bigger than most modern connectors and thus somewhat inconvenient, lots of equipment has switched to other connectors including the RJ-45 and DE-9 connectors in your picture. That adapter was likely intended to enable a connection between a server or network equipment with an RJ-45 serial port and another device with a DE-9 serial port.
    – kasperd
    yesterday





    The RS-232 standard specifies DB25 connectors. Since DB25 connectors are bigger than most modern connectors and thus somewhat inconvenient, lots of equipment has switched to other connectors including the RJ-45 and DE-9 connectors in your picture. That adapter was likely intended to enable a connection between a server or network equipment with an RJ-45 serial port and another device with a DE-9 serial port.
    – kasperd
    yesterday





    4




    4




    @kasperd, If you want to get technical, RS-232 describes the interface between a computer or computer termnial (a.k.a., "Data Terminal Equipment", or "DTE"), and a modem (a.k.a., "Data Communication Equipment", or "DCE"). These days, when we say "RS-232" we ignore almost the entire thing, except for its very lowest level---line coding and framing.
    – Solomon Slow
    yesterday




    @kasperd, If you want to get technical, RS-232 describes the interface between a computer or computer termnial (a.k.a., "Data Terminal Equipment", or "DTE"), and a modem (a.k.a., "Data Communication Equipment", or "DCE"). These days, when we say "RS-232" we ignore almost the entire thing, except for its very lowest level---line coding and framing.
    – Solomon Slow
    yesterday




    1




    1




    @SolomonSlow Exactly. My point is there are parts of that standard which are no longer in use today including the form factor of the connector. The depicted adapter is for conversion between two of the connectors which vendors have chosen to use instead of the larger DB25 connector.
    – kasperd
    yesterday




    @SolomonSlow Exactly. My point is there are parts of that standard which are no longer in use today including the form factor of the connector. The depicted adapter is for conversion between two of the connectors which vendors have chosen to use instead of the larger DB25 connector.
    – kasperd
    yesterday










    up vote
    8
    down vote














    I've got an RJ45 to D9 RS232 Adapter that I want to use to control an RS232 device in the following config:




    Whether you can accomplish your goal depends on exactly what this "adapter" that you have can do.

    There certainly are "serial to Ethernet converters" designed for the connection you proposed:




    Laptop RJ45 Ethernet port -> Cat6 patch lead -> D9 RS232 adapter -> RS232 Device




    which looks a lot like the product application:
    enter image description here.




    So what is a serial Ethernet converter used for?



    Most commonly it is used for connecting a serial RS232, RS485 or RS422 device such as a serial printer, barcode scanner, scale, GPS, sensor or any other consumer or industrial device with a serial interface, to a computer over a standard LAN network.

    The advantage of this is obvious; you will be able to control, monitor and communicate with your serial device remotely from a central computer.






    How does a serial Ethernet converter work?



    The circuitry inside the converter can convert IP/TCP packets to serial data and also convert serial data to IP/TCP packets, so it works in both directions.
    Before you can start using the converter you need to install driver software on your computer. This driver software is also called virtual COM software because it creates a virtual COM port in your computer's Device Manager when the converter is connected to your computer. Virtual COM software is usually included with the converter, at least if you buy from a reputable seller.



    Once the virtual COM port has been created by the Serial to Ethernet converter's driver software the COM port will show up in your computer's Device Manager as if it was a standard built-in COM port, however it actually is the COM port in the converter at the other end of the Ethernet.





    Images of serial to Ethernet converters








    share|improve this answer


















    • 2




      These converters are cool and useful, but I don't think I'd call something that requires its own power supply an 'adapter'. OP could probably use this if his serial device needed to be controlled remotely tho.
      – JPhi1618
      2 days ago






    • 4




      "I don't think I'd call something that requires its own power supply an 'adapter'" -- Anything with a digital IC is going to require power. USB adapters (e.g. the USB to RS-232 serial adapter mentioned in another answer) have the advantage that the USB connection provides the power for the converter chip. Ethernet is a not a bus like USB, so there is no power (unless you have PoE).
      – sawdust
      2 days ago







    • 5




      Isn't this missing the point of the question? The user's laptop ethernet port can not be used to drive a serial connection. Yes it can connect over a LAN to one of these devices, but that's not the question.
      – cpt_fink
      2 days ago






    • 1




      Very true. Maybe I'm in the minority but I've always reserved "adapter" for something that is a truly dumb pin-to-pin connection. Now that you mention it I have seen others use "USB to serial adapter" quite a bit (and for similar products).
      – JPhi1618
      2 days ago






    • 2




      @cpt_fink -- The OP wants to "to control an RS232 device", not "drive a serial connection" (whatever that means) as you claim. The description of the serial Ethernet converter states that "you will be able to control ... your serial device remotely from a ... computer." How is that not a perfect answer to the OP's question?
      – sawdust
      2 days ago















    up vote
    8
    down vote














    I've got an RJ45 to D9 RS232 Adapter that I want to use to control an RS232 device in the following config:




    Whether you can accomplish your goal depends on exactly what this "adapter" that you have can do.

    There certainly are "serial to Ethernet converters" designed for the connection you proposed:




    Laptop RJ45 Ethernet port -> Cat6 patch lead -> D9 RS232 adapter -> RS232 Device




    which looks a lot like the product application:
    enter image description here.




    So what is a serial Ethernet converter used for?



    Most commonly it is used for connecting a serial RS232, RS485 or RS422 device such as a serial printer, barcode scanner, scale, GPS, sensor or any other consumer or industrial device with a serial interface, to a computer over a standard LAN network.

    The advantage of this is obvious; you will be able to control, monitor and communicate with your serial device remotely from a central computer.






    How does a serial Ethernet converter work?



    The circuitry inside the converter can convert IP/TCP packets to serial data and also convert serial data to IP/TCP packets, so it works in both directions.
    Before you can start using the converter you need to install driver software on your computer. This driver software is also called virtual COM software because it creates a virtual COM port in your computer's Device Manager when the converter is connected to your computer. Virtual COM software is usually included with the converter, at least if you buy from a reputable seller.



    Once the virtual COM port has been created by the Serial to Ethernet converter's driver software the COM port will show up in your computer's Device Manager as if it was a standard built-in COM port, however it actually is the COM port in the converter at the other end of the Ethernet.





    Images of serial to Ethernet converters








    share|improve this answer


















    • 2




      These converters are cool and useful, but I don't think I'd call something that requires its own power supply an 'adapter'. OP could probably use this if his serial device needed to be controlled remotely tho.
      – JPhi1618
      2 days ago






    • 4




      "I don't think I'd call something that requires its own power supply an 'adapter'" -- Anything with a digital IC is going to require power. USB adapters (e.g. the USB to RS-232 serial adapter mentioned in another answer) have the advantage that the USB connection provides the power for the converter chip. Ethernet is a not a bus like USB, so there is no power (unless you have PoE).
      – sawdust
      2 days ago







    • 5




      Isn't this missing the point of the question? The user's laptop ethernet port can not be used to drive a serial connection. Yes it can connect over a LAN to one of these devices, but that's not the question.
      – cpt_fink
      2 days ago






    • 1




      Very true. Maybe I'm in the minority but I've always reserved "adapter" for something that is a truly dumb pin-to-pin connection. Now that you mention it I have seen others use "USB to serial adapter" quite a bit (and for similar products).
      – JPhi1618
      2 days ago






    • 2




      @cpt_fink -- The OP wants to "to control an RS232 device", not "drive a serial connection" (whatever that means) as you claim. The description of the serial Ethernet converter states that "you will be able to control ... your serial device remotely from a ... computer." How is that not a perfect answer to the OP's question?
      – sawdust
      2 days ago













    up vote
    8
    down vote










    up vote
    8
    down vote










    I've got an RJ45 to D9 RS232 Adapter that I want to use to control an RS232 device in the following config:




    Whether you can accomplish your goal depends on exactly what this "adapter" that you have can do.

    There certainly are "serial to Ethernet converters" designed for the connection you proposed:




    Laptop RJ45 Ethernet port -> Cat6 patch lead -> D9 RS232 adapter -> RS232 Device




    which looks a lot like the product application:
    enter image description here.




    So what is a serial Ethernet converter used for?



    Most commonly it is used for connecting a serial RS232, RS485 or RS422 device such as a serial printer, barcode scanner, scale, GPS, sensor or any other consumer or industrial device with a serial interface, to a computer over a standard LAN network.

    The advantage of this is obvious; you will be able to control, monitor and communicate with your serial device remotely from a central computer.






    How does a serial Ethernet converter work?



    The circuitry inside the converter can convert IP/TCP packets to serial data and also convert serial data to IP/TCP packets, so it works in both directions.
    Before you can start using the converter you need to install driver software on your computer. This driver software is also called virtual COM software because it creates a virtual COM port in your computer's Device Manager when the converter is connected to your computer. Virtual COM software is usually included with the converter, at least if you buy from a reputable seller.



    Once the virtual COM port has been created by the Serial to Ethernet converter's driver software the COM port will show up in your computer's Device Manager as if it was a standard built-in COM port, however it actually is the COM port in the converter at the other end of the Ethernet.





    Images of serial to Ethernet converters








    share|improve this answer















    I've got an RJ45 to D9 RS232 Adapter that I want to use to control an RS232 device in the following config:




    Whether you can accomplish your goal depends on exactly what this "adapter" that you have can do.

    There certainly are "serial to Ethernet converters" designed for the connection you proposed:




    Laptop RJ45 Ethernet port -> Cat6 patch lead -> D9 RS232 adapter -> RS232 Device




    which looks a lot like the product application:
    enter image description here.




    So what is a serial Ethernet converter used for?



    Most commonly it is used for connecting a serial RS232, RS485 or RS422 device such as a serial printer, barcode scanner, scale, GPS, sensor or any other consumer or industrial device with a serial interface, to a computer over a standard LAN network.

    The advantage of this is obvious; you will be able to control, monitor and communicate with your serial device remotely from a central computer.






    How does a serial Ethernet converter work?



    The circuitry inside the converter can convert IP/TCP packets to serial data and also convert serial data to IP/TCP packets, so it works in both directions.
    Before you can start using the converter you need to install driver software on your computer. This driver software is also called virtual COM software because it creates a virtual COM port in your computer's Device Manager when the converter is connected to your computer. Virtual COM software is usually included with the converter, at least if you buy from a reputable seller.



    Once the virtual COM port has been created by the Serial to Ethernet converter's driver software the COM port will show up in your computer's Device Manager as if it was a standard built-in COM port, however it actually is the COM port in the converter at the other end of the Ethernet.





    Images of serial to Ethernet converters









    share|improve this answer














    share|improve this answer



    share|improve this answer








    edited yesterday

























    answered 2 days ago









    sawdust

    13.6k12437




    13.6k12437







    • 2




      These converters are cool and useful, but I don't think I'd call something that requires its own power supply an 'adapter'. OP could probably use this if his serial device needed to be controlled remotely tho.
      – JPhi1618
      2 days ago






    • 4




      "I don't think I'd call something that requires its own power supply an 'adapter'" -- Anything with a digital IC is going to require power. USB adapters (e.g. the USB to RS-232 serial adapter mentioned in another answer) have the advantage that the USB connection provides the power for the converter chip. Ethernet is a not a bus like USB, so there is no power (unless you have PoE).
      – sawdust
      2 days ago







    • 5




      Isn't this missing the point of the question? The user's laptop ethernet port can not be used to drive a serial connection. Yes it can connect over a LAN to one of these devices, but that's not the question.
      – cpt_fink
      2 days ago






    • 1




      Very true. Maybe I'm in the minority but I've always reserved "adapter" for something that is a truly dumb pin-to-pin connection. Now that you mention it I have seen others use "USB to serial adapter" quite a bit (and for similar products).
      – JPhi1618
      2 days ago






    • 2




      @cpt_fink -- The OP wants to "to control an RS232 device", not "drive a serial connection" (whatever that means) as you claim. The description of the serial Ethernet converter states that "you will be able to control ... your serial device remotely from a ... computer." How is that not a perfect answer to the OP's question?
      – sawdust
      2 days ago













    • 2




      These converters are cool and useful, but I don't think I'd call something that requires its own power supply an 'adapter'. OP could probably use this if his serial device needed to be controlled remotely tho.
      – JPhi1618
      2 days ago






    • 4




      "I don't think I'd call something that requires its own power supply an 'adapter'" -- Anything with a digital IC is going to require power. USB adapters (e.g. the USB to RS-232 serial adapter mentioned in another answer) have the advantage that the USB connection provides the power for the converter chip. Ethernet is a not a bus like USB, so there is no power (unless you have PoE).
      – sawdust
      2 days ago







    • 5




      Isn't this missing the point of the question? The user's laptop ethernet port can not be used to drive a serial connection. Yes it can connect over a LAN to one of these devices, but that's not the question.
      – cpt_fink
      2 days ago






    • 1




      Very true. Maybe I'm in the minority but I've always reserved "adapter" for something that is a truly dumb pin-to-pin connection. Now that you mention it I have seen others use "USB to serial adapter" quite a bit (and for similar products).
      – JPhi1618
      2 days ago






    • 2




      @cpt_fink -- The OP wants to "to control an RS232 device", not "drive a serial connection" (whatever that means) as you claim. The description of the serial Ethernet converter states that "you will be able to control ... your serial device remotely from a ... computer." How is that not a perfect answer to the OP's question?
      – sawdust
      2 days ago








    2




    2




    These converters are cool and useful, but I don't think I'd call something that requires its own power supply an 'adapter'. OP could probably use this if his serial device needed to be controlled remotely tho.
    – JPhi1618
    2 days ago




    These converters are cool and useful, but I don't think I'd call something that requires its own power supply an 'adapter'. OP could probably use this if his serial device needed to be controlled remotely tho.
    – JPhi1618
    2 days ago




    4




    4




    "I don't think I'd call something that requires its own power supply an 'adapter'" -- Anything with a digital IC is going to require power. USB adapters (e.g. the USB to RS-232 serial adapter mentioned in another answer) have the advantage that the USB connection provides the power for the converter chip. Ethernet is a not a bus like USB, so there is no power (unless you have PoE).
    – sawdust
    2 days ago





    "I don't think I'd call something that requires its own power supply an 'adapter'" -- Anything with a digital IC is going to require power. USB adapters (e.g. the USB to RS-232 serial adapter mentioned in another answer) have the advantage that the USB connection provides the power for the converter chip. Ethernet is a not a bus like USB, so there is no power (unless you have PoE).
    – sawdust
    2 days ago





    5




    5




    Isn't this missing the point of the question? The user's laptop ethernet port can not be used to drive a serial connection. Yes it can connect over a LAN to one of these devices, but that's not the question.
    – cpt_fink
    2 days ago




    Isn't this missing the point of the question? The user's laptop ethernet port can not be used to drive a serial connection. Yes it can connect over a LAN to one of these devices, but that's not the question.
    – cpt_fink
    2 days ago




    1




    1




    Very true. Maybe I'm in the minority but I've always reserved "adapter" for something that is a truly dumb pin-to-pin connection. Now that you mention it I have seen others use "USB to serial adapter" quite a bit (and for similar products).
    – JPhi1618
    2 days ago




    Very true. Maybe I'm in the minority but I've always reserved "adapter" for something that is a truly dumb pin-to-pin connection. Now that you mention it I have seen others use "USB to serial adapter" quite a bit (and for similar products).
    – JPhi1618
    2 days ago




    2




    2




    @cpt_fink -- The OP wants to "to control an RS232 device", not "drive a serial connection" (whatever that means) as you claim. The description of the serial Ethernet converter states that "you will be able to control ... your serial device remotely from a ... computer." How is that not a perfect answer to the OP's question?
    – sawdust
    2 days ago





    @cpt_fink -- The OP wants to "to control an RS232 device", not "drive a serial connection" (whatever that means) as you claim. The description of the serial Ethernet converter states that "you will be able to control ... your serial device remotely from a ... computer." How is that not a perfect answer to the OP's question?
    – sawdust
    2 days ago











    up vote
    4
    down vote













    The physical signalling, and even more so the logical protocols, used by Ethernet are completely different from those of serial ports, so it's impossible to directly connect a laptop's LAN port to a device's serial port.



    However, the same connector is often used for both. I think the usage of an "RJ45" connector for serial console was made popular by Cisco, but network devices from other vendors use the same connector. If you have an adapter with a DE-9 on the other end, and an "RJ45" on the other, it's most likely a Cisco-style console cable. Like this one (image from Wikipedia):



    enter image description here



    To connect your laptop to a serial port of a device locally, just get a USB serial port adapter. They should be readily available and drivers for the common ones (FT232R and PL2303) can be found for most operating systems.



    However, if your use case is to connect to a serial port remotely, as in over the network, then that won't work. You'll need something that connects to the network and talks with the serial port of your device. There are commercially available devices that do just that (terminal servers), but you could solve that with another serial-equipped computer too.






    share|improve this answer
























      up vote
      4
      down vote













      The physical signalling, and even more so the logical protocols, used by Ethernet are completely different from those of serial ports, so it's impossible to directly connect a laptop's LAN port to a device's serial port.



      However, the same connector is often used for both. I think the usage of an "RJ45" connector for serial console was made popular by Cisco, but network devices from other vendors use the same connector. If you have an adapter with a DE-9 on the other end, and an "RJ45" on the other, it's most likely a Cisco-style console cable. Like this one (image from Wikipedia):



      enter image description here



      To connect your laptop to a serial port of a device locally, just get a USB serial port adapter. They should be readily available and drivers for the common ones (FT232R and PL2303) can be found for most operating systems.



      However, if your use case is to connect to a serial port remotely, as in over the network, then that won't work. You'll need something that connects to the network and talks with the serial port of your device. There are commercially available devices that do just that (terminal servers), but you could solve that with another serial-equipped computer too.






      share|improve this answer






















        up vote
        4
        down vote










        up vote
        4
        down vote









        The physical signalling, and even more so the logical protocols, used by Ethernet are completely different from those of serial ports, so it's impossible to directly connect a laptop's LAN port to a device's serial port.



        However, the same connector is often used for both. I think the usage of an "RJ45" connector for serial console was made popular by Cisco, but network devices from other vendors use the same connector. If you have an adapter with a DE-9 on the other end, and an "RJ45" on the other, it's most likely a Cisco-style console cable. Like this one (image from Wikipedia):



        enter image description here



        To connect your laptop to a serial port of a device locally, just get a USB serial port adapter. They should be readily available and drivers for the common ones (FT232R and PL2303) can be found for most operating systems.



        However, if your use case is to connect to a serial port remotely, as in over the network, then that won't work. You'll need something that connects to the network and talks with the serial port of your device. There are commercially available devices that do just that (terminal servers), but you could solve that with another serial-equipped computer too.






        share|improve this answer












        The physical signalling, and even more so the logical protocols, used by Ethernet are completely different from those of serial ports, so it's impossible to directly connect a laptop's LAN port to a device's serial port.



        However, the same connector is often used for both. I think the usage of an "RJ45" connector for serial console was made popular by Cisco, but network devices from other vendors use the same connector. If you have an adapter with a DE-9 on the other end, and an "RJ45" on the other, it's most likely a Cisco-style console cable. Like this one (image from Wikipedia):



        enter image description here



        To connect your laptop to a serial port of a device locally, just get a USB serial port adapter. They should be readily available and drivers for the common ones (FT232R and PL2303) can be found for most operating systems.



        However, if your use case is to connect to a serial port remotely, as in over the network, then that won't work. You'll need something that connects to the network and talks with the serial port of your device. There are commercially available devices that do just that (terminal servers), but you could solve that with another serial-equipped computer too.







        share|improve this answer












        share|improve this answer



        share|improve this answer










        answered yesterday









        ilkkachu

        590212




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