Reference Manual

PMAC 2 Software Reference

84 PMAC I-Variable Specifiation

Ix28 Motor x In-position Band

Range

0 .. 8,388,607

Units

1/16 Count

Default

160 (10 counts)

Remarks

Ix28 determines the magnitude of the maximum following error at which Motor x will be

considered “in position” when not performing a move. Several things happen when the

motor is “in-position”. First, a status bit in the motor status word is set. Second, if all other

motors in the same coordinate system are also “in-position”, a status bit in the coordinate

system status word is set. Third, for the hardware-selected (FPD0/-FPD3/) coordinate

system – if I2=0 – or for the software addressed (&n) coordinate system – if I2=1 – outputs

to the control panel port and to the interrupt controller are set.

Technically, five conditions must be met for a motor to be considered “in-position”:

1. The motor must be in closed-loop control

2. The desired velocity must be zero;

3. The magnitude of the following error must be less than this parameter;

4. The move timer must not be active;

5. The above four conditions must all be true for (I7+1) consecutive scans

The move timer is active during any programmed or non-programmed move, including

DWELLs and DELAYs in a program – if you wish this bit to come true during a program,

you must do an indefinite wait between some moves by keeping the program trapped in a

WHILE loop that has no moves or DWELLs. More sophisticated in-position functions (for

instance, ones that require several consecutive scans within the band) can be implemented

using PLC programs. See the program examples section.

Note:

The units of this parameter are 1/16 of a count, so the value should

be 16 times the number of counts in the in-position band.

Example

M140->Y:$0814,0 ; Motor 1 in-position bit

...

WHILE (M140=0) WAIT ; Delay indefinitely until in-position is true

M1=1 ; Set output once in-position