RobotStudio event

Pos1 of CNV1 does not change during conveyor belt operation (DSQC 377B)

Hello ladies and gentlemen,

I have 2 IRC5 each with a DSQC 377B, an IO board (DSGC 652) and a DeviceNet (sst-dn3-pci-1). There are unsorted parts on the conveyor belt, which will later be recognized by a camera and then tracked by the 377B unit.
I connected the encoder according to the plan.

On the IO-Board and the Queue Tracking Module, MS and NS light up green continuously, so they do not give an error. The LEDs on the DeviceNet are also green (Comm and HL T)
Do I have to connect the frequency inverter to the robot? (I am currently starting it manually and that is enough for my project)

However, under Jogging, on the Flex Pendant, POS1 of CNV1 does not change when I run the conveyor belt.
Does anyone have any idea what my error is and how I can fix it?

When I look at the I/O system of "Qtrack1", "c1DReady" is always changing between on/off (1/0) and "c1NullSpeed" is permanently at 1. Otherwise nothing happens no matter if I have the conveyor belt on or off.

Thank you very much