RS-485 testing

[roland2807]

Hello

I have a computer with 7 RS-232/422/485 ports. It is not problem to test the RS-232 interface, but how can I test the RS-485 port. Can I connect 2 port together or can I use a loopback connector. If yes, then how should the loop back connector be made?
I would prefer not to use an external converter if possible.

[David (PassMark)]

For 422/485 I would used a RS232 to 485 converter and then use our RS232 loopback plugs.

[malte]

Hi,
we faced the same problem with RS422 and RS485.

Using RS485 to RS232 converter will not work because RS485 is a kind of none Duplex, you can either send or receive so you'd need a kind of active loopback. BurnIn can't handle that (yet).

RS422 can work with a dedicated loopback, you need to loop

TX+ to RX+
TX- to RX-
than use BurnIn Test without handshake. If you have RS422 that also has RTS+/- and CTS +/- BurnIn Test can not handle these signals, as it expects also DSR, DTR, RTS Loops.

Kind Regards
Malte