CC-Link Woes

[Carples 0]

I have a strange problem. I have a CC-Link network with 2 * PLC's and 4 * Remote I/O modules. All was working fine, I was using several instances of the RIRD and RIWR instructions with no problems. Then I added a Piltz M1P saftey controller with a CC-Link 1.1 module. All of a sudden all the RIRD and RIwr instructions stopped working, but the cyclic data was still working correctly. I removed the Pilz from the system and every thing was fine. I had to remove data cable run as well about 6m. I have since moved all data transfers through the cyclic data registers, and re added the Pilz module and its has been fine for a week. Now I have had a problem with one of the Remote I/O flashing L ERR and losing L Run momentarialy at random intervals. Since a stop button is hooked upto it, this stops my machine. Further investigation has revieled that 1 other module is also doing this. so the 2nd last a 4th last modules from master are playing up. Could this be due to cable length approaching limit for 5m comms speed, I will be trying a reduction of this to next setting down on friday. CC-Link Diagnostic program is complete crap says every thing is fine dispite network being unstable. It should be more like the Ethernet one and include data on lost packets and corrupted packets, allowing for actual identification of issues.

[Crossbow 295]

It would be great if there was such a thing as lost packets to count. Ethernet can lose packets, where a dedicated token passing network like CC-Link cannot. My recommendation would be to look at your code and write some additional code to monitor when a station leaves the network. Count how many times it happens, and time stamp it. That way you can determine what else in the PLC or machine could be causing an issue. CC-Link is a very robust network when properly wired and grounded.

[Carples 0]

I ended up turning the speed down 1 setting and the system stablised, and is no longer causing trouble