Hoping to catch a seasoned guru's attention on this thread who knows these drives.
We have 3 PowerFlex 700s controlling fan motors in a cooling tower that cool jacket water temps in big gas engines. We have ControLogix 5000 plc’s talking to a remote I/O rack which talks to the PF 700’s through a 20-COMM-E module. A PID logic written by the integrators who put this stuff in controls the VFD's which vary speed of the fans from 20 Hz to 60 Hz.
Works great, as long as the Ethernet link is not lost. Here is the problem from day one. Every time the engines shutdown unexpectedly or sometimes even brought down normally, you can be certain that the link between the Logix and VFD's has been compromised or lost. So the next time the engines start, if you don't manually hit the green button on the powerflex's, you pretty much don't have fan control and will overheat engines. Even though the Logic is executing locally in the plc, it is not being communicated to the powerflex modules. I’ve been asking management to send me to training on these stupid things, but I can see that’s not gonna happen . I know zero about the 700’s, how they talk to local plc, the settings, or config. Any information on why this is happening or anything in general on these would be deeply appreciated. When I drill down within rslogix, I can see the drives, but can not see them through rslinx. I think because they are talking through a remote rack with a different IP base.
We have 3 PowerFlex 700s controlling fan motors in a cooling tower that cool jacket water temps in big gas engines. We have ControLogix 5000 plc’s talking to a remote I/O rack which talks to the PF 700’s through a 20-COMM-E module. A PID logic written by the integrators who put this stuff in controls the VFD's which vary speed of the fans from 20 Hz to 60 Hz.
Works great, as long as the Ethernet link is not lost. Here is the problem from day one. Every time the engines shutdown unexpectedly or sometimes even brought down normally, you can be certain that the link between the Logix and VFD's has been compromised or lost. So the next time the engines start, if you don't manually hit the green button on the powerflex's, you pretty much don't have fan control and will overheat engines. Even though the Logic is executing locally in the plc, it is not being communicated to the powerflex modules. I’ve been asking management to send me to training on these stupid things, but I can see that’s not gonna happen . I know zero about the 700’s, how they talk to local plc, the settings, or config. Any information on why this is happening or anything in general on these would be deeply appreciated. When I drill down within rslogix, I can see the drives, but can not see them through rslinx. I think because they are talking through a remote rack with a different IP base.
Last edited: