GFK-0467K Chapter 4 Series 90-30/20/Micro Instructions Set 4-107
4
Section 9: Control Functions

This section describes the control functions, which may be used to limit program execution and

alter the way the CPU executes the application program. (Refer to Chapter 2, section 1, “PLC

Sweep Summary,” for information on the CPU sweep.

Function Description Page

CALL Causes program execution to go to a specified subroutine block. 4-108
DOIO Services for one sweep a specified range of inputs or outputs immediately. (All
inputs or outputs on a module are serviced if any reference locations on that
module are included in the DO I/O function. Partial I/O module updates are not
performed.) Optionally, a copy of the scanned I/O can be placed in internal
memory, rather than the real input points.
4-109
SER Sequential Event Recorder— collects data based on an event trigger. A function
control block contains user-supplied information about function block
execution, channel descriptions and operation parameters.
4-114
END Provides a temporary end of logic. The program executes from the first rung to
the last rung or the END instruction, whichever is encountered first. This
instruction is useful for debugging purposes, but it is not permitted in SFC
programming (refer to the Note on page 4-114).
4-123
MCR
and
MCRN
Programs a Master Control Relay. An MCR causes all rungs between the MCR
and its subsequent ENDMCR to be executed without power flow. Logicmaster
90-30/20/Micro software supports two forms of the MCR function, a non-nested
form (MCR) and a nested form (MCRN).
4-124
ENDMCR
and
ENDMCRN
Indicates that the subsequent logic is to be executed with normal power flow.
Logicmaster 90-30/20/Micro software supports two forms of the ENDMCR
function, a non-nested form (ENDMCR) and a nested form (ENDMCRN).
4-127
JUMP
and
JUMPN
Causes program execution to jump to a specified location (indicated by a
LABEL, see below) in the logic. Logicmaster 90-30/20/Micro software
supports two forms of the JUMP function, a non-nested form (JUMP) and a
nested form (JUMPN).
4-128
LABEL
and
LABELN
Specifies the target location of a JUMP instruction. Logicmaster 90-30/20/Micro
software supports two forms of the LABEL function, a non-nested form
(LABEL) and a nested form (LABELN).
4-130
COMMENT Places a comment (rung explanation) in the program. After programming the
instruction, the text can be typed in by “zooming” into the instruction. 4-131
SVCREQ Requests one of the following special PLC services:
•Change/Read Task State and Number of Words to Checksum.
•Change/Read Time-of-Day Clock.
•Shut Down the PLC.
•Clear Fault Tables.
•Read Last-Logged Fault Table Entry.
•Read Elapsed Time Clock.
•Read I/O Override Status.
•Read Master Checksum
•Interrogate I/O
•Read Elapsed Power Down Time
4-132
PID Provides two PID (proportional/integral/derivative) closed-loop control
algorithms:
•Standard ISA PID algorithm (PIDISA).
• Independent term algorithm (PIDIND).
4-165