Chapter 4. Ladder Diagram (LD) Programming
GFK-2950C
February 2018
209
EndMCRN
The End Master Control Relay instruction marks the end of a section of logic begun with a Master
Control Relay instruction. When the MCRN associated with the ENDMCRN is active, the ENDMCRN
causes program execution to resume with normal power flow. When the MCRN associated with the
ENDMCRN is not active, the ENDMCRN has no effect.
ENDMCRN must be tied to the power rail; there can be no logic before it in the rung; execution
cannot be conditional.
ENDMCRN has a name that identifies it and associates it with the corresponding MCRN(s). The
ENDMCRN function has no outputs; there can be nothing after an ENDMCR instruction in a rung.
Operands for MCRN/ENDMCRN
The Master Control Relay function has a single operand, a name that identifies the MCRN. This name
is used again with an ENDMCRN instruction. The MCRN has no output.
Parameter
Description
Optional
Name
(???? )
The name associated with the MCRN that starts the section of logic.
No
Example of MCRN/ENDMCRN
The example at right an MCRN named
Sec_MCRN
nested inside the MCRN named
First_MCRN
.
Whenever the V_I0002 contact allows power flow into
the MCRN function, program execution will continue
without power flow to the coils until the associated
ENDMCRN is reached. If the V_I0001 and V_I0003
contacts are ON, the V_Q0001 coil is turned OFF and
the SET coil V_Q0003 maintains its current state.
Содержание PACSystems RX7i
Страница 357: ......
Страница 466: ...Chapter 9 Diagnostics GFK 2950C February 2018 451...