C Memory Areas - Omron CPM1 - PROGRAMING MANUAL 02-2001 Programming Manual

CPM1/CPM1A Memory Areas
Memory Area Structure
The following memory areas can be used with the CPM1/CPM1A.
Data area
1
IR area
Input area
Output area
Work area
SR area
TR area
2
HR area
2
AR area
1
LR area
2
Timer/Counter area
2
DM area Read/write
2
Error log
4
Read-only
4
PC Setup
Note 1. IR and LR bits that are not used for their allocated functions can be used as work bits.
2. The contents of the HR area, AR area, Counter area, and read/write DM area are backed up by a capaci-
tor. The backup time varies with the ambient temperature, but at 25_C, the capacitor will back up
memory for 20 days. If the power supply is off longer than the backup time, memory contents will be
cleared and AR1314 will turn ON. (This flag turns ON when data can no longer be retained by the built-in
capacitor.) Refer to 2-1-2 Characteristics in the CPM1 Operation Manual for a graph showing the back-
up time vs. temperature.
3. When accessing a PV, TC numbers are used as word data; when accessing Completion Flags, they are
used as bit data.
4. Data in DM 6144 to DM 6655 cannot be overwritten from the program, but they can be changed from a
Programming Device.
SR Area
These bits mainly serve as flags related to CPM1/CPM1A operation or contain present and set values for various
functions. The functions of the SR area are explained in the following table.
Note "Read-only" words and bits can be read as status in controller PC operation, but they cannot be written from
the ladder program. Bits and words that are "Not used" are also read-only.
Appendix C
Memory Areas
Words
IR 000 to IR 009 IR 00000 to IR 00915
(10 words) (160 bits)
IR 010 to IR 019 IR 01000 to IR 01915
(10 words) (160 bits)
IR 200 to IR 231 IR 20000 to IR 23115
(32 words) (512 bits)
SR 232 to SR 255 SR 23200 to SR 25515
(24 words) (384 bits)
--- TR 0 to TR 7
(8 bits)
HR 00 to HR 19 HR 0000 to HR 1915
(20 words) (320 bits)
AR 00 to AR 15 AR 0000 to AR 1515
(16 words) (256 bits)
LR 00 to LR 15 LR 0000 to LR 1515
(16 words) (256 bits)
TC 000 to TC 127 (timer/counter numbers)
DM 0000 to DM 0999 ---
DM 1022 to DM 1023
(1,002 words)
DM 1000 to DM 1021 ---
(22 words)
DM 6144 to DM 6599 ---
(456 words)
DM 6600 to DM 6655 ---
(56 words)
Bits
These bits can be allocated to the external
I/O terminals. /O e a s
Work bits can be freely used within the pro-
gram.
These bits serve specific functions such as
flags and control bits.
These bits are used to temporarily store
ON/OFF status at program branches.
These bits store data and retain their ON/
OFF status when power is turned off.
These bits serve specific functions such as
flags and control bits.
Used for a 1:1 data link with another PC.
3
The same numbers are used for both timers
and counters.
DM area data can be accessed in word
units only. Word values are retained when
the power is turned off.
Used to store the error code of errors that
occur. These words can be used as ordi-
nary read/write DM when the error log func-
tion isn't being used.
Cannot be overwritten from program.
Used to store various parameters that con-
trol PC operation.
Function
569