Reference Manual

Turbo PMAC/PMAC2 Software Reference
Turbo PMAC Global I-Variables 157
Ixx97 Motor xx Position Capture & Trigger Mode
Range: 0 - 3
Units: none
Default: 0
Ixx97 controls the triggering function and the position capture function for triggered moves on Motor xx.
These triggered moves include homing search moves, on-line jog-until-trigger moves, and motion
program RAPID-mode move-until-trigger. Ixx97 is a 2-bit value: bit 0 controls the how the capture of the
trigger position is done (the post-trigger move is relative to the trigger position), and bit 1 specifies what
the trigger condition is.
Hardware Capture: If Ixx97 is set to 0 or 2 (bit 0 = 0), Turbo PMAC will use the hardware-captured
position in the Servo IC as the trigger position. This is the “flag-capture” register associated with the flag
set used for the motor, as specified for Ixx25. In order for this to work properly, the position-loop
feedback for Motor xx, as specified by Ixx03, and the conversion table, must be received through the
encoder counter of the same hardware interface channel as used for the flag set (e.g. if flag set 2 is used,
encoder 2 must be used for position-loop feedback). The advantage of the hardware position capture is
that it is immediate, and accurate to the exact count at any speed.
Software Capture: If Ixx97 is set to 1 or 3 (bit 0 = 1), Turbo PMAC will use a software-captured
position for the trigger position. In this case, Turbo PMAC uses the register whose address is specified
by Ixx03, usually a register in the encoder conversion table, for the trigger position. The advantage of
software capture is that it can be used with any type of feedback, or when the position encoder channel is
not the same as the flag channel. The disadvantage is that the software capture can have up to 1
background cycle delay (typically 2-3 msec), which limits the accuracy of the capture.
Input Trigger: If Ixx97 is set to 0 or 1, (bit 1 = 0), Turbo PMAC will use the input capture trigger flag
in the Servo IC flag register addressed by Ixx25 as the trigger for the move. This input trigger is created
by an edge of the index input and a flag input for the channel as specified by I7mn2 and I7mn3 for the
selected Channel n of Servo IC m, or if a MACRO flag register is selected by Ixx25 with bit 18 of Ixx25
set to 1, the input trigger condition is set by MI-variables on the MACRO station.
Error Trigger: If Ixx97 is set to 2 or 3, (bit 1 = 1), Turbo PMAC will use the warning following error
status bit in the motor status word as the trigger for the move. When this bit changes from 0 to 1 because
the magnitude of the following error for the motor has exceeded the warning limit in Ixx12, Turbo PMAC
will consider this the trigger condition for the triggered move. Because there is nothing in this mode that
can create a hardware capture, only software capture should be used with error trigger (Ixx97 = 3).
Summarizing the values of Ixx97, and their effect:
 Ixx97 = 0: Input trigger, hardware position capture
 Ixx97 = 1: Input trigger, software position capture
 Ixx97 = 2: Error trigger, hardware position capture (not useful!)
 Ixx97 = 3: Error trigger, software position capture
In non-Turbo PMACs, this function is controlled by bits 16 and 17 of Ix03.
Ixx98 Motor xx Third-Resolver Gear Ratio
Range: 0 - 4095
Units: Second-resolver turns per third resolver turn
Default: 0
Ixx98 tells Turbo PMAC the gear ratio between the second (medium) and third (coarse) resolvers for a
triple-resolver setup for Motor xx. It is expressed as the number of turns (electrical cycles) the second
resolver makes in one full turn (electrical cycle) of the third resolver.