First G120 for me, I'm mostly on the Logix side. CPU 1516-3 PN/DP, G120 with a CU240E-2 PN and a PM240-2, TIA V17 with Startdrive, standard telegram 1. Drive is green in device view, no buffer entries.
From the PLC I write control word 16#047F and speed setpoint 16#2000 into the telegram with DPWR_DAT. The status word comes back, r0052 in Startdrive shows bit 0, ready to switch on, and that's where it sits. Motor never turns, no fault, no alarm. I re-assigned the device name from scratch and checked p0840 is r2090.0 so the ON command comes off the telegram.
In Logix I'd set the Start bit and go. What does the G120 want that I'm not giving it? Any pointers welcome.
Is the speed setpoint scaled right? On my bench drive 16#4000 is 100 percent, so 16#2000 is only half, and I once had a minimum speed set that made it look dead.
> 16#4000 is 100 percent
Yes, 2000 is 50 percent and p1080 minimum is 0. Tried 4000 as well. Still ready to switch on, still nothing.
The drive is waiting for an edge. Bit 0 of the control word, OFF1, must go from 0 to 1 while the other bits are already set. If the PLC writes 16#047F from the first cycle, the drive has never seen bit 0 low, so there is no rising edge and it stays in ready to switch on. r0052.0 says exactly that: ready, waiting for ON.
Sequence: write 16#047E first, one or more cycles, then 16#047F. The drive goes to operation enabled, r0052.2, and turns. For a stop, back to 16#047E. Nothing else in your list is wrong.
Longer version with the control word bits is here: https://plctr.com/utilizing-plc-for-motor-control-and-drive-systems/
Wrote 047E for a second at startup and then 047F on the run command. Drive went to operation enabled, motor turned, speed followed the setpoint. Ran it all afternoon.
So the drive never saw a rising edge on OFF1, the PLC had been sitting at 047F since power up. Writing 047E first and then 047F on the run command is all it wanted.
Same as a PowerFlex wanting its start bit to pulse rather than sit high, and I should have thought of that. What I haven't tested is what happens when the CPU goes to STOP and comes back with the run bit already high, not sure if it wants the edge again. Thanks gunther, and annaz for making me check the minimum speed.
Marking solved.
plctr.com team