Holding Area (H) - Omron CP1E CPU UNIT SOFTWARE User Manual

5-4

Holding Area (H)

Overview
The Holding Area is part of the internal memory of the CPU Unit. It is used in programming. Unlike the
input bits and output bits in the CIO Area, I/O to and from external devices is not refreshed for this area.
These words retain their content when the PLC is turned ON or the operating mode is switched
between PROGRAM mode and RUN or MONITOR mode.
Precautions for Safe Use
With an E-type CPU Unit or with an N/NA-type CPU Unit without a Battery, the contents of the
DM Area (D) *, Holding Area (H), the Counter Present Values (C), the status of Counter Comple-
tion Flags (C), and the status of bits in the Auxiliary Area (A) related to clock functions may be
unstable when the power supply is turned ON.
* This does not apply to areas backed up to EEPROM using the DM backup function.
If the DM backup function is being used, be sure to refer to 3-2-4 Initializing I/O Memory at Star-
tup for details.
Notation
H 2 0 . 0 2
Bit number: 02
Word number: 20
I/O memory area designator: H
Range
The Holding area contains 50 words with addresses ranging from H0 to H49.
Applications
The Holding Area is used when you want to resume operation after a power interruption using the same
status as before the power interruption.
CP1E CPU Unit Software User's Manual(W480)
5 I/O Memory
5
5-9