Red Lion G307K & Modbus TCP/IP

Hi everyone,
First time I have used the Kadet Series of HMI's. I have used the Standard G306-310 and Graphite Series of HMI.

I am trying to communicate with a device via Modbus TCP/IP and I am not having any luck what so ever. I am not even getting junk or numbers that would indicate that I have my byte or bit order reversed. I have done this with a G308 before with no issue to the same device. I know there are many differences between the Kadet series and the rest of the RL HMI line up. SO is there anything in the Kadet that would keep me from using Modbus TCP/IP? Anything different in this area that I may have missed?

Just looking for any ideas I can get because I am at a loss here. I am going to download some Modbus testing software and try and read the registers with my computer and go from there. In the mean time if you have any advice I would be really grateful for it.
Thanks

I have done Modbus TCP on a G307K2 before. It was just for a test--communicating with Excel on a PC--but I'm pretty sure it worked. I might be able to dig up the old database tonight. Are you using the Kadet as the master or slave?

The Kadet is the master.

Well I ended up solving my issues. In the Communications page I had the IGNORE READ EXCEPTIONS set to NO. As soon as I set it to YES things started working. Thanks for the help.

Bullzi said:

Well I ended up solving my issues. In the Communications page I had the IGNORE READ EXCEPTIONS set to NO. As soon as I set it to YES things started working. Thanks for the help.

Click to expand...

If you had to set that to YES and changing to NO fixed it, it is possible that your Read Blocks are set too large. What I mean by that is that if you need to pull registers 1,2,3, and 5, but 4 is invalid, the display may try to simplify the Read instruction by pulling 1,2,3,4,5 at the same time which would result in a read exception.

I may be wrong, but check your list of registers and see if the Modbus map of the device you are reading from does not use a register that is in a 32 register range around two registers you *are* reading (if you left your default settings alone).