I have two Anybus AB7007-C modules, that are setup the same, except for their IP addresses. They both communicate to an identical Modbus devices. Both devices are on node 1, which I think is why we have two modules. The logic to get each individual status word is exactly the same for both devices, which I created using the manual. The Byte sizes to and from the devices are identical, and setup to the same sizes using the Anybus Configurator. The problem I am having is that on one I get the desired feed back of no errors, and the other one I get alternating retransmission errors.
I get the 0x1F - No errors always on one. The other I get it alternating between the 0x1F code and 0x00 Retransmission Counter Updated, and see the counter rising. I have gone through both configurations, and PLC IO and don’t see any reason why one behaves different then the other, because they both seem to be identical.
What I do notice different is that the SR_HS_SEND feed back on the one that seems to work fine is always on, and the other alternates on and off.
My setup is master mode with the control/status parameter set to enable but no startup lock.
I tried to program in such a way to just read the status register, because I don’t need to send anything I think, but cannot seem to get it to work, and had to write to the control register to work with the below flow charts in the manual. For the control word I only use the CR_HS_CONFIRM and CR_HS_SEND to get my status, and the rest are left with a zero value.
I am quite stuck and kindly ask for some assistance, and can only think that there is somehow a difference in the anybus modules themselves.