Ok so we had two SMC EX250 valve manifolds drop out on two different sides of our network. Then we lost a Red Lion HMI and another EX250. We replaced one of the EX250 manifolds and got it communicating with no problems. We replaced another one and could not get it to talk. We found that the Can-H and the shield were swapped on the two manifolds that started the whole thing. We wired them correctly and then they had no more issues. So we lost three EX250 SI units and one Devicenet module for the G310 HMI. The problem is solved and everything is fine now. I just wanted to ask if anyone has experienced anything like this. I'm thinking that there is no possible way the devices will communicate wired like that. Any thoughts?
