Reference Guide

PMAC Quick Reference Guide
38 Programming PMAC
Warning:
Certain registers that are under PMAC’s automatic control, particularly those used
in the servo calculations, can cause problems if written to them directly.
Range X-Memory Y-Memory Type
$0000 - $00FF Fixed-Use calculation Registers Fixed-Use calculation Registers Internal DSP
Memory
$0100 - $17FF Fixed-Use calculation Registers Fixed-Use calculation Registers External Static RAM
(Battery Backed)
$1800 - $BBFF User Buffer Storage Space User Buffer Storage Space External Static RAM
(Battery Backed)
$BC00 - $BFFF User-Written Servo Storage M-Variable Definitions External Static RAM
(Battery Backed)
$C000 - $C03F DSP-Gate Registers
$D000 - $DFFF Bits 0 to 15 Bits 0 to 15 Dual-Ported RAM
$E000 - $F000 VME Setup Registers (bits 0 to 7) Mailbox Registers (bits 0 to 7) VME bus registers
$F000 - $FFFF N / A I / O Registers
User Buffer Storage Space
• 256 Motion Programs can be held. All programs must be stopped before any can be opened.
• All programs must be stopped before any can run.
• A PLC program can be opened while others are running.
• Buffers must be defined from end of memory toward beginning. Buffers must be deleted from
beginning of memory to end.
Encoder Conversion Table
PMAC uses a multiple-step process to work with its feedback and master position information, and with
external time-base sources, to provide maximum power and flexibility. For most PMAC users with
quadrature encoders, this process can be virtually transparent, with no need to worry about the details.
However, some users will need to understand this conversion process in some detail to make the changes
necessary to use other types of feedback, to optimize their system, or to perform special functions. The
PMAC Executive Program for PC-compatible computers has a special editing screen for the conversion
table that makes viewing it and changing it very easy.