Reference Manual
  PMAC 2 Software Reference 
338  PMAC Program Command Specification 
PLC programs are specified by number, and may be specified in a command singularly, 
in a list (separated by commas), or in a range of consecutively numbered programs. 
If no buffer is open when this command is sent to PMAC, it will be executed 
immediately as an on-line command. 
Example 
PAUSE PLC 1 
PAUSE PLC 4,5 
PAUSE PLC 7..20 
PAU PLC 3,8,11 
PAU PLC 0..31 
See Also 
I-variable I5 
On-line commands ENABLE PLC, DISABLE PLC, <CONTROL-D>, PAUSE PLC, 
RESUME PLC, LIST PLC 
Program command ENABLE PLC, DISABLE PLC, RESUME PLC 
PRELUDE 
Function 
Specify automatic subroutine call function 
Type 
Motion program 
Syntax 
PRELUDE1{command} 
PRELUDE0 
where: 
•  {command} is a subprogram call from the set CALL{constant}, 
G{constant}, M{constant}, T{constant}, D{constant}. 
Remarks 
The PRELUDE1 command permits automatic insertion of a subprogram call before each 
subsequent motion command (e.g., X10Y10) or other letter-number command (e.g., 
L10) other than a line label in the motion program. The action taken is equivalent to 
inserting the call into the program text before each subsequent motion command or letter-
number command. 
The subprogram call to be performed can be specified in the PRELUDE1 command either 
as a CALL command, or as a G, M, T, or D code. The value following the CALL or code 
letter must be a constant. It cannot be a variable or expression. It does not have to be an 
integer. If the routine called in the subprogram starts with a READ statement, the motion 
or letter-number command itself can become arguments for the subprogram call. Any 
motion command within a PRELUDE1 subroutine or subprogram call is executed directly 
as a motion command, without an automatic subroutine call in front of it. 
PMAC will only execute the PRELUDE1 function if the motion or letter-number 
command is found at the beginning of a program line or immediately after the line label. 
If another type of command occurs earlier on the program line, no PRELUDE1 function 
will be executed before the motion or letter-number command. If the command is on a 
line that is already in a subroutine or subprogram reached by a CALL or GOSUB 
command, no PRELUDE1 function will be executed. 
Each PRELUDE1 command supersedes the previous PRELUDE1 command. It is not 
possible to nest automatic PRELUDE1 calls, but an automatic PRELUDE1 call can be 
nested within explicit subroutine and subprogram calls. 
PRELUDE0 disables any automatic subroutine call. 










