Reference Manual

PMAC 2 Software Reference

240 PMAC On-Line Command Specification

On-line commands J+, J-, J/, J=, J={constant}, J:{constant}, J=*, J:*, J^*

J^*

Function

Jog to specified variable distance from present actual position

Scope

Motor specific

Syntax

J^*

Remarks

This command causes the addressed motor to jog the distance specified in the motor’s

variable jog position/distance register relative to the present actual position. Jogging

acceleration and velocity are determined by the values of Ix19-Ix22 in force at the time of

this command. Compare to J:* , which is a jog relative to the present commanded position.

The variable jog position/distance register is a floating-point register with units of counts. It

is best accessed with a floating-point M-variable. The register is located at PMAC address

L:$082B for motor 1, L:$08EB for motor 2, etc. (suggested M-variable Mx72).The usual

procedure is to write the destination position to this register by assigning a value to the M-

variable, then issuing the J^* command.

PMAC will reject this command if the motor is in a coordinate system that is currently

running a motion program (reporting ERR001 if I6 is 1 or 3).

Example

M172->L:$082B ; Define #1 variable jog position/distance reg.

#1HMZ ............... ; Declare present position to be zero

M172=3000...... ; Assign distance value to register

#1J^* ............... ; Jog Motor 1 this distance; if following error at

........................... ; command was 3, end cmd. pos. will be 2997

#1J^* ............... ; Jog Motor 1 this distance; if following error at

........................... ; command was 2, end cmd. pos. will be 5995

M172=P1*SIN(P2) ; Assign new distance value to register

#1J^* ............... ; Jog Motor 1 this distance

#1J= ; Return to prejog target position