Reading PLC register using ModBusTCPCom in .Net results in address not found

Question

I have to update an old WinForms application. The application uses the AdvancedHMI .NET software. I am connecting to the PLC (AutomationDirect DirectLogic 06 Series) with no issues, and various other registers are being read accurately. I am expecting to get a 4 digit value from the register.
I am reading it like so:

Dim rawValue As String = BeltSpeedModbusTcpCom.Read("V3103")

When I read the register I get address not found.

The ladderlogic diagram I am was given is:

I have tried adjusting the address, using 03103, F3103, and other combinations. We can view the address values in real time in the PLC using software the customer has.

Answer 1

According to Page 4-13 of the DL-06 manual, the “V” register number is Octal. Try reading “1603”, which is octal 3103 converted to decimal.