Reference Manual

PMAC 2 Software Reference

60 PMAC I-Variable Specifiation

Ix04 Motor x Velocity Loop Feedback Address

Range

Legal PMAC X addresses

Units

Legal PMAC X addresses

Default

Same as Ix03

Remarks

Ix04 holds the address of the position feedback device that PMAC uses for its velocity-

loop feedback information. For a motor with only a single feedback device (the usual

case), this must be the same as Ix03. For a motor with dual feedback (motor and load), use

Ix04 to point to the encoder on the motor, and Ix03 to point to the encoder on the load.

If the velocity-loop feedback device is the same device as is used for commutation (if

PMAC is doing the commutation), then both Ix04 and Ix83 (commutation feedback

address) must reference the same device. However, Ix04 typically points to the converted

data – a register in the Encoder Conversion table – while Ix83 must point directly to the

DSPGATE encoder register.

The instructions for setting this parameter are identical to those for Ix03, except that there

are no address extension bits.

Note:

When planning which channels to use when connecting the position

and velocity encoders, remember that the channel pointed to by

Ix25 is used for the Overtravel, Amplifier Fault, and Home Flag

inputs.