Omron SYSMAC CJ - REFERENCE MANUAL 08-2008 Reference Manual page 256

Sequence Control Instructions
216
The MILH(517)/MILR(518) instruction turns OFF the Interlock Status Bit
(operand D) when the interlock is in engaged and turns ON the bit when the
interlock is not engaged. Consequently, the Interlock Status Bit can be moni-
tored to check whether or not the interlock for a given interlock number is
engaged.
Input condition
Interlocked program
section
Nesting
Interlocks are nested when an interlocked program section (MILH(517)/
MILR(518) and MILC(519) combination) is placed within another interlocked
program section (MILH(517)/MILR(518) and MILC(519) combination). Inter-
locks can be nested up to 16 levels.
Nesting can be used for the following kinds of applications.
• Example 1
Interlocking the entire program with one condition and interlocking a part
of the program with another condition (1 nesting level)
• A1 and A2 are interlocked when the Emergency Stop Button is ON.
• A2 is interlocked when Conveyor RUN is OFF.
Input condition ON
(Normal operation) Input condition OFF
MILH
n
d
Normal Outputs interlocked.
operation (Outputs OFF,
Interlock timers reset, etc.)
Status Bit Interlock Status Bit
(d) ON (d) OFF
MILC
n
Global interlock
(Emergency stop)
A1 (Peripheral processing)
Partial interlock
(Conveyor RUN)
A2 (Conveyor operation)
Section 3-5