AB7072 Reading Zeros

Hi, I have an AB7072 connect to a 2-Wire RS485 subnetwork. The ACM Node Monitor is just showing zero’s for the read values. LED 5 is a solid red, showing that the subnet has stopped, and checking the data logging, there’s no information transactions in the RX column. According to the information I have from the manufacturer, the subnetwork is configured correctly, and the port is connected to Pin 9 = RS485A(-), Pin 8 = RS485B(+), and Pin 5 = Signal Gnd. Any ideas on what to try next?


I would double check the RS485 connector, and ensure the plug/cable does not have any broken connections.

Can you provide a backup of the Anybus Configuration Manager configuration? You should be able to save the .cfg file. I would like to review the Subnet Settings, and subnet transactions.

On the slave, is there any indication that it is receiving the RX data from the communicator?

There’s continuity through the 3 wires on the RS485. I’m not sure what you mean by “on the slave.” I clicked the start logging button, then stopped it, and the RX column was blank.

This is communicating with an AB CompactLogix PLC as well through ethernet/ip

heateranybus.cfg (16.0 KB)
heateranybus.cfx (8.6 KB)

What are the serial settings for the slave?

As for indication on the slave, is there any LED activity occurring on the slave?