Lindy USB 2 RS485 Converter Cable, how to conneced to +/- RS485 device?

[GertJL]

Hi All,

I have recently acquire a 2nd hand Lindy usb<>RS485 converter cable. I found this forum-link, since I have a problem interpreting how to connect the db9-male pins to my RS485 transceiver device which has a connection marked Gnd, +/- thus 3-pins, thus half-duplex. I assume the +/- is similar to the transceiver ic output driver/receiver A/B (ti SN65HVD12DR) inside the device. On the Lindy user-guide the DB9 pins 1,2,3,4 5(gnd) refers to

 

Pin Def Desciption

1 DM (1)Tx/Rx-

2 DP (1)Tx/Rx+

3 DP (2)Tx/Rx+

4 DM (2) Tx/Rx-.

5 GND

The rest of the pins (6-9) I see as Handshake signals.

 

Now, my query, how do I connect my RS485-device's +/- pins, since it is only 2 pins??.

I could make the assumption that the Lindy cable make provision for 2 rs485 devices, on pins 1&2 / pins3&4.

Since my RS485 is half-duplex, can I then connect the device's +- pins to any pair, 1&2 or 3&4 and

do one have to configure any parameter on the xp usb driver to make it aware half-duplex, which pair 1&2 or 3&4 in use?

 

However the xp installed driver only install one comport.

 

As you can probably deduce from this writing , I am not an it skilled-tech person,

however, I do know that one is suppose to be able to drive and communicate with only 1xpair of twisted wires, thus how to connect my device 2pins (+/-) to Lindy cable (gnd optional)

 

Many thanks for your helpful feedback.

 

Regards,

Gert

Lindy USB2RS485 Cable.pdf