Appendix C
Memory Areas
582
Data area
Function
Bits
Words
AR area
2
AR 00 to AR 15
(16 words)
AR 0000 to AR 1515
(256 bits)
These bits serve specific functions such as
flags and control bits. AR 04 to 07 are used
as slaves. Refer to
AR Area
.
LR area
1
LR 00 to LR 15
(16 words)
LR 0000 to LR 1515
(256 bits)
Used for a 1:1 data link with another SRM1,
CQM1 or C200HS PC.
Timer/Counter area
2
TC 000 to TC 127 (timer/counter numbers)
3
Timers and counter use the TIM, TIMH(15),
CNT and CNTR(12) instructions. The same
numbers are used for both timers and
counters.
Timer/counter numbers should be specified
as bits when dealing with timer/counter
present values. The counter data will be
stored even when the SRM1 power is
turned off or operation is stopped or started.
When timer/counter are treated as up-flags
the number should be specified as relay
data.
DM area
Read/write
2
DM 0000 to DM 1999
(2,000 words)
---
DM area data can be accessed in word
units only. Word values are retained when
the power is turned off, or operation started
or stopped.
Read/write areas can be read and written
freely within the program.
Error log
4
DM 2000 to DM 2021
(22 words)
---
Used to store the time of occurrence and
error code of errors that occur. Refer to
7-5
Coding Right-hand Instructions.
Read-only
4
DM 6144 to DM 6599
(456 words)
---
Cannot be overwritten from program.
PC Setup
4
DM 6600 to DM 6655
(56 words)
---
Used to store various parameters that con-
trol PC operation.
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, LR area, Counter area, and read/write DM area are backed up by a capaci-
tor. At 25
C, the capacitor will back up memory for 20 days. Refer to
2-1-2 Characteristics
in the
SRM1
Master Control Unit Operation Manual
for a graph showing the backup 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 SRM1 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.
Word(s)
Bit(s)
Function
Read/
write
Page
SR 240
to
SR 247
00 to 15
Not used.
SR 248,
SR 249
00 to 15
Reserved.
SR 250,
SR 251
00 to 15
Not used.
