computerwolf
Lifetime Supporting Member
I have an AB relay module (1746-OW16) controlling a PowerFlex 4 drive, that in turn is powering a conveyor. There are actually many conveyors at my plant that have the same configuration.
The PF4 is configured for 2-wire control, with terminal 1 being being the Stop command and jumpered to terminal 11 (+24V), and terminal 2 being the Start command. The drive is also configured as the "Source". Based on my extremely limited knowledge of "Source" and "Sink", it's my understanding that the "source" provides the voltage/current and the "sink" receives it.
If that's the case, how in the world is the PLC output relay card "telling" the drive to start? I tried measuring voltage, both DC and AC and get nothing on AC. On DC, I get +5V whether the conveyor's running or not.
But the kicker is that when I measured it the following day, I got 35vdc!
More info: The cable connecting the Drive with the PLC is 2-wire shielded and the Start signal runs through an e-stop relay before being terminated at OUT2, while the stop signal runs through an MCR that's connected to a terminal on the module called V1.
I really feel like I'm missing something here. I can usually figure these things out, but this one's kicking my rear.
Any help would be greatly appeciated.
John
Sherman, TX
The PF4 is configured for 2-wire control, with terminal 1 being being the Stop command and jumpered to terminal 11 (+24V), and terminal 2 being the Start command. The drive is also configured as the "Source". Based on my extremely limited knowledge of "Source" and "Sink", it's my understanding that the "source" provides the voltage/current and the "sink" receives it.
If that's the case, how in the world is the PLC output relay card "telling" the drive to start? I tried measuring voltage, both DC and AC and get nothing on AC. On DC, I get +5V whether the conveyor's running or not.
But the kicker is that when I measured it the following day, I got 35vdc!
More info: The cable connecting the Drive with the PLC is 2-wire shielded and the Start signal runs through an e-stop relay before being terminated at OUT2, while the stop signal runs through an MCR that's connected to a terminal on the module called V1.
I really feel like I'm missing something here. I can usually figure these things out, but this one's kicking my rear.
Any help would be greatly appeciated.
John
Sherman, TX