User's Manual

Geo MACRO Drive User Manual
74 Setting Up Primary Feedback
WARNING:
An unreliable phasing reference method can lead to a runaway condition. Test the
phasing reference method carefully to make sure it works properly under all
conceivable conditions. Make sure the Ixx11 fatal following error limit is active
and as tight as possible so the motor will be killed quickly in the event of a serious
phasing search error.
Absolute Phase Power-On Position Address and Format: Ixx81, Ixx91, Ixx75
To read an R/D converter for absolute phase position, Ixx81 is set equal to the MACRO node’s position
feedback register, and Ixx91 is set to $180000.
Motor phase offset variable Ixx75 contains the difference between the absolute resolver position and the
resulting phase angle position (if any).
Absolute Servo Power-On Position Address and Format: Ixx10, Ixx95
Turbo PMAC will obtain the absolute servo power-on position through the MACRO ring. To read an
R/D converter for absolute power on position, Ixx10 specifies the address of the register containing the
position data from the Geo MACRO drive, which points to the ECT (See Appendix under Ixx95). And
Ixx95 is set to $5B0000, Parallel X-register, unsigned value, 19 bits, Motor xx will do parallel data read
of the Turbo PMAC memory at the address specified by Ixx10.
Motor offset variable Ixx26 contains the difference between the absolute resolver position and the
resulting motor position (if any).
Scaling the Feedback Units
The Geo Drive R/D converter is a 12-bit converter. It reports 4096 separate states per electrical cycle of
the resolver (per mechanical revolution for a typical 2-pole resolver, per half revolution for a 4-pole
resolver.