Functions - Omron SYSMAC CPM2B Operation Manual

Introduction
4-1-1

Functions

IR Area
Work Bits
SR Area
TR Area
HR Area
AR Area
LR Area
Timer/Counter Area
DM Area
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The functions of the IR Area are explained below.
IR Area bits in the input and output words are allocated to terminals on the
CPU Board and Expansion I/O Boards. They reflect the ON/OFF status of
input and output signals. Input bits begin at IR 00000, and output bits begin at
IR 01000.
IR words that are not allocated to inputs or outputs can be used as work
words.
The work bits can be used freely within the program. They can only be used
within the program, however, and not for direct external I/O.
These bits mainly serve as flags for CPM2B operation or contain present and
set values for various functions. SR 253 to SR 255 are read-only. Refer to 4-3
SR Area for details on the various bit functions.
When a complex ladder diagram cannot be programmed in mnemonic code
just as it is, these bits are used to temporarily store ON/OFF execution condi-
tions at program branches. They are used only for mnemonic code. When
programming directly with ladder diagrams using the Support Software, TR
bits are automatically processed for you.
The same TR bits cannot be used more than once within the same instruction
block, but can be used again in different instruction blocks. The ON/OFF sta-
tus of TR bits cannot be monitored from a Programming Device.
These bits retain their ON/OFF status even after the PLC power supply has
been turned OFF or when operation begins or stops. They are used in the
same way as work bits.
These bits mainly serve as flags related to PLC operation. These bits retain
their status even after the PLC power supply has been turned OFF or when
operation begins or stops. Refer to 4-4 AR Area for details on the various bit
functions.
When the CPM2B is linked 1:1 with another CPM2B or a CPM1/CPM1A/
CPM2A/CPM2C/SRM1(-V2), a CQM1, a C200HS or a C200HX/HG/HE PLC,
these bits are used to share data.
LR words can be used as work words when they are not used for a 1:1 PLC
Link.
This area is used to manage timers and counters created with TIM, TIMH(15),
TMHH(––), TIML(––), CNT, and CNTR(12). The same numbers are used for
both timers and counters and each number can be used only once in the user
program. Do not use the same TC number twice even for different instruc-
tions.
Use TC numbers 000 to 003 for TIMH(15) and TC numbers 004 to 007 for
TMHH(––). When these timer numbers are used, timing is performed as an
interrupt process and the cycle time is not affected.
TC numbers are used to create timers and counters, as well as to access
Completion Flags and present values (PVs). If a TC number is designated for
word data, it will access the present value (PV); if it is used for bit data, it will
access the Completion Flag for the timer/counter.
DM Area data is accessed in word units only. The contents of the DM Area are
retained even after the PLC power supply has been turned OFF or when oper-
ation begins or stops.
DM words DM 0000 to DM 1999 and DM 2022 to DM 2047 can be used freely
in the program; other DM words are allocated specific functions.
DM 2000 to DM 2021 contain the error log information. Refer to Section 4-6
Error Log for details on the error log.
DM 6600 to DM 6655 contain the PLC Setup. Refer to 4-5 PLC Setup for
details.
Section 4-1
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