Brew Chip
Member
I'm in the midst of commissioning a number of these units and I'm having a trouble with a flying (re)start. The short background is that my PLC is using Modbus to control a blower motor that is integral to a third-party heater system. The heater sends me a blower request; I send 1151 in the control word to start the drive and send the heater an ACK when the blower is up to speed.
The issue is that when the heater short-cycles, the drive won't spin back up until it comes to a complete stop. It's a big blower and the spin-down usually takes so long that the heater throws an alarm. (I can't/don't want to go down the rabbit hole of the short-cycle itself. That's in said third-party's court.) We have enabled parameters for a flying start and it works as desired when we put the drive in local control, but not from Modbus commands. My AOI for drive control is pretty simple, I send 1151 to run, 1150 otherwise, and no logic on my end is checking for a full stop before sending a start. I see that 1150 is explicitly a ramp to stop command, does flying start only work when coasting (which would be command 1149)?
The issue is that when the heater short-cycles, the drive won't spin back up until it comes to a complete stop. It's a big blower and the spin-down usually takes so long that the heater throws an alarm. (I can't/don't want to go down the rabbit hole of the short-cycle itself. That's in said third-party's court.) We have enabled parameters for a flying start and it works as desired when we put the drive in local control, but not from Modbus commands. My AOI for drive control is pretty simple, I send 1151 to run, 1150 otherwise, and no logic on my end is checking for a full stop before sending a start. I see that 1150 is explicitly a ramp to stop command, does flying start only work when coasting (which would be command 1149)?