[Quick link: Getting AL-31 when using hall-less commutation? Click here.]
The P Drive supports incremental encoders with hall-less commutation as an option. To use hall-less commutation, go to the Motor/Encoder Setup page and select one of the hall-less options.
There are four hall-less commutation options available:
|Optimum search 1||Commutate the motor using a minimum motion algorithm the first time the drive is enabled following power-up.|
|Stepper open loop search 1||Commutate the motor by forcing the motor's electrical angle the first time the drive is enabled following power-up. The motor will move up to one electrical cycle.|
|Optimum search 2||Commutate the motor using a minimum motion algorithm every time the drive is enabled.|
|Stepper open loop search 2||Commutate the motor by forcing the motor's electrical angle every time the drive is enabled. The motor will move up to one electrical cycle.|
Prior to firmware version 2.00, when using hall-less commutation, the P Drive will generate an AL-31 alarm if none of the hall inputs are connected. To prevent this from happening, place a jumper between pin 5 (hall phase U) and pin 7 (digital ground) on the drive's feedback port.
With firmware version 2.00 or higher, this jumper no longer is needed. New P Drives are shipping with this firmware. Existing units in the field can be updated in the field with Drive Support Tool software. Be certain to use version v0.88 or newer (older version of DST can cause bootloader problem):
Note: Hall-less commutation cannot be used with motors with brakes or heavy mechanical load where the motor shaft cannot move approximately +/- 1/8 rev when enabled.
If using an external motion controller including the ACR74C/ACR78C or ACR9000, the drive fault output isn't held low while the drive doing this algorithm. Thus the controller thinks it's enabled and ready for motion immediately. In testing, the hall-less commutation Optimum search takes about1.7 seconds so place in a delay (for ACR with AcroBasic DWL 2) after the drive on command is issued and then that gives enough time to complete.
If the encoder does not a have Z channel (also known as an N or Index channel), pins 8 and 9 should be left unconnected. To prevent the drive from generating an AL-34 alarm (encoder Z phase open), go to the Fault Configuration page in Drive Support Tool and check the box to disable AL-34.
Fault Configuration page:
Note during the Commutation, the drive will display C-run and then switch to P-run, S-run or t-run depending upon the drive control mode.
01AUG2022 JHOAGLAND Update with 2.00firmware