User`s manual

7-28 Motion Mate™ DSM314 for Series 90™-30 PLCs User's Manual – January 2001 GFK-1742A
7
Wait Command
The WAIT command is similar to the DWELL command. Instead of generating no motion for a
specified period of time, a WAIT stops program motion until a specified CTL bit turns ON. Thus
motion stops any time a WAIT is encountered, even if the CTL bit is ON before the WAIT is
reached in the program. The trigger to continue the program can be any of the twelve CTL bits.
If, in the previous example, WAIT were substituted for DWELL, the motion profile would be the
same except the second PMOVE would not start until the CTL bit turned ON. If the CTL bit was
ON when the program reached the WAIT, the second PMOVE would begin immediately after the
first PMOVE finished.
Also, if WAIT were used instead of DWELL in the previous example, CMOVEs and PMOVEs
would generate similar velocity profiles. The WAIT will stop motion whether the previous move
is a CMOVE or PMOVE.
A single WAIT command only applies to one axis. Therefore, in a multi-axis program, you must
designate an axis number with each WAIT command. For example: WAIT AXIS1 CTL001. If
you wish to have both axes wait in a multi-axis program, you must use a separate WAIT
command for each axis.
Subroutines
The DSM314 can store up to ten separate programs and forty subroutines. Subroutines can be
defined as two types:
single-axis
and
multi-axis
. Subroutines are available for all motion
programs created with the Motion Editor. Commands within single-axis subroutines do not
contain an axis number; this allows single-axis subroutines to be called from any single-axis
program (the commands in the subroutine use the axis number specified by the calling program).
Commands within multi-axis subroutines contain axis numbers just like commands within multi-
axis programs. Multi-axis subroutines can only be called from multi-axis programs or
subroutines. Single-axis subroutines can only be called from single-axis programs or subroutines.
For example, a single-axis program for axis 1 and a single-axis program for axis 2 can call the
same single-axis subroutine simultaneously. Each subroutine must be assigned a unique number
between 1 and 40.
Subroutines are programmed using the CALL command, which specifies the subroutine number
to be called. When a CALL is encountered during program execution, program execution is
redirected to the subroutine. When the subroutine completes, program execution resumes at the
command after the CALL command. Subroutines can be called from another subroutine, but once
a subroutine has been called, it must complete before it can be called again for the same axis.
Thus, recursion is not allowed.
Block Numbers and Jumps
Block numbers are used as reference points within a motion program and to control jump testing.
A %AI data word displays the current block number which can be monitored to ensure correct
program execution or to determine when events should occur. A block number can also serve as a
JUMP command destination. Jumps may be unconditional or conditional. An unconditional jump