Reference Manual
  PMAC 2 Software Reference 
120  PMAC I-Variable Specifiation 
If backlash tables are used, Ix86 represents the backlash at motor zero position; values in 
the table should represent the difference between the backlash at a given position and Ix86. 
Note: 
The units of this parameter are 1/16 of a count so the value should 
be 16 times the number of counts of backlash compensation desired. 
Example 
If you find that you have a backlash on reversal of motor direction of 7.5 encoder counts, 
you would set Ix86 to 7.5 * 16 = 120. 
See Also 
I-variables I99, Ix64, Ix65, Ix68, Ix85 
On-line commands DEFINE BLCOMP, DELETE BLCOMP 
Backlash Compensation (Setting Up a Motor) 
Coordinate System x I-Variables 
x = Coordinate System Number (&x, x = 1 to 8) 
Ix87  Coordinate System x Default Program Acceleration Time 
Range 
0 .. 8,388,607 
Units 
msec 
Default 
0 (so Ix88 controls) 
Remarks 
Ix87 sets the default time for commanded acceleration for programmed blended LINEAR 
and CIRCLE mode moves in Coordinate System x. It also provides the default segment 
time for SPLINE mode moves. The first use of a TA statement in a program overrides this 
value. 
Note: 
Even though this parameter makes is possible not to specify 
acceleration time in the motion program, you are strongly 
encouraged to use TA in the program and not rely on this parameter, 
unless you must keep to a syntax standard that does not support this 
(e.g. RS-274 “G-Codes “). Specifying acceleration time in the 
program along with speed and move modes makes it much easier 
for later debugging. 
If the specified S-curve time (see Ix88, below) is greater than half the specified 
acceleration time, the time used for commanded acceleration in blended moves will be 
twice the specified S-curve time. 
The acceleration time is also the minimum time for a blended move; if the distance on a 
feedrate-specified (F) move is so short that the calculated move time is less than the 
acceleration time, or the time of a time-specified (TM) move is less than the acceleration 
time, the move will be done in the acceleration time instead. This will slow down the 
move. 
Note: 
The acceleration time will be extended automatically when any 
motor in the coordinate system is asked to exceed its maximum 
acceleration rate (Ix17) for a programmed LINEAR-mode move 
with I13=0 (no move segmentation). 










