Red Lion MODBUS RTU to King Gage

[phuz]

I'm a little confused about the wiring from a King Gage to a Red Lion G3 unit.
We are using the MODBUS protocol from the King Gage. I took a patch cable and plugged the Rj45 into the Red Lion's RS485 port. I stripped the other end and put Pin #1 (ORG/WHT) on the King's "B" terminal, Pin #2 (ORG) on the King's "A" terminal, and Pin #6 (GRN) on the King's "GND" terminal. The red light is lit, but I don't appear to be getting data. This is a canned Crimson program from King Gage, so I didn't touch any of the config inside the program.

 

[harryting]

The first thing I always do is to switch the A and B on RS485.

If that doesn't work. I would go try to troubleshoot the components one at a time. Get a USB-RS485 adopter for your laptop, download one of the modbus master simulator (google) and see if you get get the gauge to respond to you. It that works, then do the something except with a modbus slave simulator on your laptop and the Redlion as master.

 

[phuz]

Well it appears to have established communications, because the comm errors go away when I plug it in now, but I am not reading any values. I set up some tags to go right to the Modbus (MODBUS 4 in this case) at register 400001. Doesn't even read a zero, just "---".