AB ML1400 Modbus TCP/IP Communications

[SRHair 0]

Hello, I'm new to setting up my controllers and communication between devices.  We wanted to see if using Modbus TCP/IP to communicate to a load bank was the right path for us.  I was able to configure my Micrologix 1400 controller Channel 1 for Modbus and set the data files.  I set up a read holding register 03 message, two write single register 06 messages and one write multiple registers 16.  I was able to read the data from the load bank, but I was unable to send any write commands.  I didn't get any errors in the messages.  I was able to send write commands through my pc to the load bank and it responded properly.  So I was thinking I must of missed something in my set up in the PLC. I'm attaching the PLC Program and the command set from the manufacturer.  Any help would be greatly appreciated.

BENCH_TEST.RSS

ALx Series Input Command.pdf

ALx Series PWR Command Page.pdf

ALx Series Setpoint Command.pdf