Rx3i cpe305 modbus tcp/ip

Hey guys,
I am currently trying to communicate a cpe305 PLC with modscan32 in a computer.I am using the ethernet port available in the PLC to talk with the modscan32 via modbus tcp/ip. I can ping the device but I get a MODBUS EXCEPTION response from the slave (the plc), so no information is actually shown. I have the cpe305 on standard modbus addressing and its firmware is 8.75. I need help my client is starting to get mad :S.

What command is Modscan sending to the PLC to generate the response? Are you sure you are trying to access a valid address?

As far as a command I am not sure I can only configure Port (502), the IP address (The plc one), and then click on connect. I am trying to see any address currently. From my understanding once the cpe305 is set as modbus addressing I should be able to access almost all memory in the PLC. I am a bit lost since this is the first time I am using this type of communication protocol.

I don't have Modscan, so I can't help you with specifics, but when you are trying to read data from the PLC you need to define exactly what you want to read. You need to specify the address of the data and the number of data points you want to read. If you don't specify a valid address you won't get any data.

whats the exception code value?

http://www.simplymodbus.ca/exceptions.htm

Guys... I was so focused on the issue and not being able to identify my issue that I was downloading to the Plc while it was still on run mode so that the hardware config with the modbus tcp/ip wasn't getting downloaded to the plc. Thanks everyone anyway, sometimes the most simple things can get you