Using a Non-7390 Motion Controller with a P-Command DriveHardware: Motion Control
Problem: I have a 7330/7340/7350 motion controller. How do I configure this card to work with a P-Command drive in Measurement and Automation Explorer? Solution: When using a 7330/7340/7350 motion controller with a P-Command drive, you should not use it in closed-loop stepper mode. In closed-loop stepper mode, the motion controller will execute pull-in moves at the end of a move if the encoder feedback is off from the target position. However, a P-Command drive receives a number of pulses and then uses its own PID control to move the motor with an analog voltage output, so a P-Command drive does not need pull-in moves. When configured incorrectly, unneccesary pull-in moves are generated which send extra pulses to the drive, changing the P-Command drive and motor’s target positions from what you had intended.  When using a 7330/7340/7350 motion controller with a P-Command drive, you should select Stepper for Type in the Axis Configuration tab in MAX, and then select Encoder for feedback. Select the Stepper Settings tab and set the Stepper Loop Mode to P-Command. Related Links: KnowledgeBase 41EGJUBE: What is P-Command Mode? KnowledgeBase 446INTAJ: What is the Difference Between P-Command and Stepper when Using National Instruments Motion Products? KnowledgeBase 27QARKOA: Stepper Motors will Work in Open Loop Mode, But Behave Incorrectly in Closed Loop Mode Product Manuals: NI PCI-7390 User Manual Attachments:
Report Date: 10/18/2006 Last Updated: 03/16/2009 Document ID: 42HHJIS4 |
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
