Lookout to CTI 2572 communication

[salesm]

Please Help!!! New to Lookout. Inherited system from a previous system integrator.

We are in the process of adding new equipments and are modifying a TI555 PLC program to control the new equipments. To minimize plant downtime, we’ve downloaded the modified program to a spare processor and then swap the processor out. Then bring the system back online.

However, once we swapped the processor, we are getting intermittent communication loss at the Lookout computers to the swapped processor. The computers are communicating normally with the other eight TI545/TI555 PLCs. Communication goes in and out every one minute or so. We are getting the "No communication response from secondary unit" alarm.

There are two Lookout computers. What we discovered is that when we disconnect Computer2 from the network, the communication loss error goes away. Also, Computer2 seems to be a client to Computer1 because when we turn off Computer1, Computer2 loses communication to all PLCs. However, I was told by plant personnel that Computer2 has its own I/O driver, but somehow, it is setup to get data from Computer1. It seems Computer2 is creating unwanted traffic on the network. Is there a way for us to verify that Computer2 has its own I/O driver?

This is very confusing because swapping the processors should not affect the network in any way as we have not changed any network configurations in the new program and also, all the network parameters are retained in the CTI 2572 Ethernet module.

We are not getting the communication error when we put the original processor back in. I read that increasing the Receive timeout period will fix this. If this does not work, are there any other suggestions?

I think we are using version 5.1.

Thank you in advance.

[Ryan.S]

So, you just changed the processor and the program, but the 2572 keeps the same.  Is there anything else changed? There must be something different...

When you disconnect the computer2, is computer1 able to communicate with the new processor?

I guess your lookout process uses the Tiway object. Is the lookout software on computer2 the development/runtime server or the runtime only server?

If it's development/runtime, you can go to edit mode, search the Tiway object in Object Explorer. But the object name is uncertain...

Another way is to open the source file(.lks) file of the process by text editor, and search it for Tiway. You will find the object name, and go back to lookout to check the object.

Even if the driver object does exist in the process, it's not sure whether they are working or not. One way to disable the driver object is just to input wrong paramters, such as ip address. And then you can check if the communication is fine.

If the lookout on computer2 is the runtime only server, you need to open and edit the process in development/runtime server.

[salesm]

So, you just changed the processor and the program, but the 2572 keeps the same.  Is there anything else changed? There must be something different...  (Nothing has changed.)

When you disconnect the computer2, is computer1 able to communicate with the new processor? (Yes. When computer2 is disconnected, everything works fine.)

We will look at computer2 next later this week.