wilkerson29847
Member
This is a very broad subject but I am really unsure how to ask it.
We have a fairly large network with several hundred IP addresses (600 +). We have mainly Micrologix and Compact Logix PLCs on our plant machinery but 4 machines each have 5 Siemens PLCs. A lot of the machines are exactly the same but with different IP addresses. For instance we have 14 waterjets the same, 24 hydraulic presses the same, etc. I have verified that there are no duplicate IP addresses and I have changed a lot of things from multicast to unicast. The problem is, if I connect machines to the network, we start having communication issues, meaning that machines stop responding and you have to disconnect them from the network and power down/power up to reset communications. It may run for a couple of hours before we have an issue or it may run for 3 days. I have been racking my brain trying to figure out why this is happening and I am having no luck. The only thing that comes to mind is that all of the RPIs that I have looked at on the various machines are set to the default of 20 ms. I am wondering if this could be the root cause. Is there a guide on what the RPIs should be set to based on what the machine function is? So as an example, a hydraulic press would have a maximum allowed RPI of 250 ms and a controller with waterjet robots would have a maximum allowed RPI of 50 ms. Any guidance would be greatly appreciated. My next step is to find someone with the experience and credentials that could come in and help me find the reason, and I am sure that would be quite expensive.
We have a fairly large network with several hundred IP addresses (600 +). We have mainly Micrologix and Compact Logix PLCs on our plant machinery but 4 machines each have 5 Siemens PLCs. A lot of the machines are exactly the same but with different IP addresses. For instance we have 14 waterjets the same, 24 hydraulic presses the same, etc. I have verified that there are no duplicate IP addresses and I have changed a lot of things from multicast to unicast. The problem is, if I connect machines to the network, we start having communication issues, meaning that machines stop responding and you have to disconnect them from the network and power down/power up to reset communications. It may run for a couple of hours before we have an issue or it may run for 3 days. I have been racking my brain trying to figure out why this is happening and I am having no luck. The only thing that comes to mind is that all of the RPIs that I have looked at on the various machines are set to the default of 20 ms. I am wondering if this could be the root cause. Is there a guide on what the RPIs should be set to based on what the machine function is? So as an example, a hydraulic press would have a maximum allowed RPI of 250 ms and a controller with waterjet robots would have a maximum allowed RPI of 50 ms. Any guidance would be greatly appreciated. My next step is to find someone with the experience and credentials that could come in and help me find the reason, and I am sure that would be quite expensive.