Hello. So we have a machine with a carriage run by a VFD driven motor. I have noticed that for some reason it periodically loses 720 pulses and then regains them shortly after, see picture. There is no pattern to it that I can find and it sometimes takes 1 second to regain the pulses and other times can be upwards of 30 seconds. It occurs at different points in the carriage's travel.
We are using a 1756-HSC with a Turck Ri-QR24 contacless encoder at 4000ppr. Voltage is good, shield is intact on the cable, encoder ring runs true to the motor shaft.
This is causing a significant difference in where the PLC thinks the carriage is at in it's travel. Any ideas?
Thanks in advance.
We are using a 1756-HSC with a Turck Ri-QR24 contacless encoder at 4000ppr. Voltage is good, shield is intact on the cable, encoder ring runs true to the motor shaft.
This is causing a significant difference in where the PLC thinks the carriage is at in it's travel. Any ideas?
Thanks in advance.