@DavideAndrea In this case, however, the “other question” is a logical follow up from the first. The first question is “How does this work?” and the second question is “Why?”

Now that you know this, what is Drive Executive telling you that the motor speed is doing when you are trying to run the pump at 0.25 RPM?

When you say that you are running the motor at 0.25 RPM, is that 0.25 RPM motor speed, or is it 0.25 RPM pump speed, which is really 7.84 RPM motor speed?

Is there a gearbox on the motor? If so, is the 0.25 RPM value the speed of the motor or the speed of the gearbox output?

Is this a scenario that was working before, and now does not? Or is trying to run at 0.25 RPM a new scenario that you have not tried before?

Which PLC are you using?

@GaretJax Something else: Touching the loose screw on terminals doesn't always produce a reliable connection. Stick some wires into the terminals, and touch your meter leads to those wires.

@GaretJax Agreed, it is unlikely that they will all be broken. Work on getting the embedded I/O to work first. If you've got O:0/0 turned on (which you do in your screenshot) and you see the indicator for O/0 on on the display (which it appears to be in your photo), then you should be reading close to 0 ohms between the VAC/VDC and O/0 pair of terminals, located just to the right of your AC power input cable. Also, check the cross reference for B3:0/0 and O:0/0 to make sure you aren't turning them off somewhere else.

@GaretJax In that case, it doesn't matter how you wire them, they won't work. Have you tested the embedded outputs that are on the main controller module, not the expansion card?