rs485

[charliehbeijer]

I open com2 on my T7A and it seems to be transmitting differential serial on pins 1 and 6, but it never goes tristate. How do you make it go tristate on the 485 bus so that other nodes may transmit? Also, is there a copy of the db9 pinout online?

[mark.monroe]

The pin outs are in the controller help file. If you are using a converter, then you should select a driver that is designed to work with 485, like the Allen-Bradley DH485 controller and it will have the cable pins.

http://ixtalk.beijerelectronics.com/vie ... hp?f=8&t=4

Pin outs for the TxA series of HMI's

Snap 2012-08-16 at 08.20.50.jpg (47.11 KiB) Viewed 9033 times

Snap 2012-08-16 at 08.21.00.jpg (50.7 KiB) Viewed 9033 times

[charliehbeijer]

Turns out my port selection had been changed to 422 accidentally. That explains why it was always driving the bus. I changed it back to 485 and it behaves as expected.