User's Manual

PMAC User Manual
Basic Motor Moves 127
• Ix03 bit 16 specifies whether the hardware-captured counter value is used as the trigger position —
suitable for incremental encoder signals, real or simulated — or the software-read position is used
instead — suitable for other types of feedback (0=hardware, 1=software). The software-read position
must be used if the following error status is used for the trigger.
PMAC will use the jog parameters Ix19-Ix22 in force at the time of the command for the pre-trigger
move, and the values of these parameters in force at the time of the trigger for the post-trigger move.
The captured value of the sensor position at the trigger is stored in a dedicated register if later access is
needed. The units are in counts; for incremental encoders, they are relative to the power-up/reset
position.
PMAC sets the motor home-search-in-progress status bit (bit 10 of the first motor status word returned on
a ? command) true (1) at the beginning of a jog-until-trigger move. The bit is set false (0) either when the
trigger is found, or at the end of the move.
PMAC also sets the motor trigger move status bit (bit 7 of the second motor status word returned on a ?
command) true at the beginning of a jog-until-trigger move, and keeps it true at least until the end of the
move. If a trigger is found during the move, this bit is set false at the end of the post-trigger move; however,
if the pre-trigger move finishes without finding a trigger, the bit is left true at the end of the move.
Therefore, this bit can be used at the end of the move to tell whether the trigger was found successfully or
not. The motor desired-velocity-zero status bit can be used to determine the end of the move.
V
T
Ix20 < 2 * Ix21
2*Ix21
Ix21 Ix21
2*Ix21
Ix21 Ix21
V
T
Ix20 > 2 * Ix21
Ix20
Ix21 Ix21
Ix20
Ix21 Ix21
Ix20 ACCELERATION TIME (JOG, HOME)
(Units: msec); integer
S-CURVE TIME (JOG, HOME)
(Units: msec); integer
V
T
Ix21=0
Ix20 Ix20
Ix21
Figure 21 Motor x Motion Variables