11-07-2005 02:53 AM
I am using a PCI-7358 motion controller card in combination with an UMI-7772 to control two brushless servos. The PCI-7358 creates the commutation for the servo’s, by using onboard commutation.
The physical encoder counts per revolution are 2048.
One motor has 4 pole pairs and the other motor has 5 pole pairs.
By using the X4-encoding the encoder counts per revolution are 8192.
When I calculate the Encoder counts per electrical cycle the result for the motor with 4 pole pairs is 2048 and the result for the motor with 5 pole pairs is 1638.4
I am using the equation:
Encoder Counts per electrical cycle = 2 * (encoder counts per revolution / number of poles)
Th motor with 5 pole pairs causes some trouble, because I have to fill in 1638 or 1639 for the variable Encoder counts per electrical cycle in MAX. (No broken numbers are allowed)
Every rotation this causes an error of 2 counts, so there is an problem with the Following Error, and the motor can start heating up.
Does anyone know how to solve this problem (except for replacing the encoder by a part with 2000 encoder counts per revolution) in MAX
Wim Kaan
11-07-2005 03:26 AM
11-10-2005 06:06 PM