PMAC Product Guide Multiple homing moves can be started together by specifying a list or range of motor numbers with the command (e.g. HOME1,3 or HOME2..6 ). Further program execution will wait for all of these motors to finish their homing moves. Separate homing commands, even on the same line (e.g. HOME1 HOME2 ) will be executed in sequence, with the first finishing before the second starts. It is not possible to execute partially overlapping homing moves from a single motion program. Note carefully the difference in syntax between the on-line command and the buffered command.
The on-line command is simply HOME or HM and it acts on the currently addressed motor, so the motor number must be specified in front of the command (e.g. #1HM ). In the buffered command, the motor number is part of the command, following immediately after HOME or HM letters (e.g. HM1 ). Homing from a PLC Program PMAC PLC programs can command homing search moves by giving on-line commands with the COMMAND"" statement (e.g. COMMAND"#1HM" ). These commands simply start the homing search move; code must be written to monitor for finishing if that is desired.
The motor number must be specified in the specific command string, or with the ADDRESS#n statement; without this statement, motor addressing is not modal within PLC programs. Motion vs. PLC Program Homing The following table summarizes the differences between homing using Motion programs and PMAC PLC programs. Zero-Move Homing To declare the current position the home position without commanding any movement, use the HOMEZ (on-line) or HOMEZn (motion program) command. These are similar to the HOME command, except that they immediately take the current commanded position as the home position. The Ix26 offset is not used with the HOMEZ command. Note:
If a following error is received when the HOMEZ command is given, the reported actual position after the HOMEZ command will not be exactly zero; it will be equal to the negative of the following error. Programming PMAC 61 Motion Programs PLC Programs Program execution point stays on the line containing the Home command until the homing move is finished. The PLC does not monitor for the start and end of the homing move automatically. Home command can be combined with programmed axis moves. Axis motion can only be performed through Jog commands. . The coordinate system must be ready to run a motion program. The coordinate system does not need to be ready to run a motion program.
Can only home motors defined in the coordinate system running the program. Can home any motor not defined in a coordinate system running a program. Motors can be homed simultaneously, one after another, or any combination of the two. Motors can be homed in any order. This includes starting one motor in the middle of another motor’s home move. The motion program must be started by an on-line command, a PLC program, or another motion program. The PLC can be started by an on-line command, a PLC program, another motion program, or automatically at power-up or reset.