I'm not sure this is the correct place for this question.

I have a console cable to configure network devices like switches (https://images-na.ssl-images-amazon.com/images/I/41LDstMTA5L.jpg)

So, I want to make an extension cable with an RS232 connector in one side and the other side with a TTL to USB connector, I already have this one https://www.aliexpress.com/item/CH340G-Module-USB-TTL-Serial-Converter-UART-Module-CH340-3-3V-5V-Switch-Upgrade-Download-Brush/32594018417.html

I saw some cables in market but I think those are not long enough to my needs, also I have the cable and just have to buy the connectors and I really want to make the cable.

My issue is that I don't know the proper connections I have to do between the connectors, I searched in google but I don't see configurations of the USB to TTL adapter with RS232 connector.

  • Some newer Cisco equipment has USB Mini-B ports, if you have the drivers, they can be configured via these ports, as opposed to the older rollover/console cables. – Davidw Oct 28 '17 at 5:52
  • That's correct David, i am using that to some equipment but no all the switches and routers have this port. – Juan Botero Oct 28 '17 at 5:54
  • 3
    You might just include a simple USB Extension cable between the USB to Serial adapter and the computer, instead of making the cable. – Davidw Oct 28 '17 at 5:57

So, i want to make an extension cable with an rs232 connector in one side and the other side with a ttl to USB connector

These cables are commercially available. Buy one.

If it isn't long enough, you can get DB-9 extension cables. (RS232 is stable over much longer distances than USB, so you're much better off extending that than USB.)

… i already have this one [link to an AliExpress CH340G module]

That won't work. That module uses TTL serial, and will be damaged by the ±12V I/O used for RS232.


Simplest solution: Just use a USB Extension cable between the computer and the USB to Serial Adapter.

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