Omron CQM1H - PROGRAM Programming Manual page 198

DM Area
Note
Read/Write DM Area
Read-only Area
(DM 6144 to DM 6568)
Error Log Area
(DM 6569 to DM 6599)
Error log area
PC Setup (see note 2)
1. The read-only area ranges from DM 6144 to DM 6568.
2. The read-only area, PC Setup, program, and expansion instruction assign-
ments can be transferred to and from the Memory Cassette as a single
block of data. See 3-11 Using Memory Cassettes for details.
The read/write area has no particular functions assigned to it and can be used
freely. It can be read and written from the program or Programming Devices.
The size of the read/write area depends upon the model of CPU Unit, as
shown in the following table.
CPU Unit
CQM1H-CPU11
CQM1H-CPU21
CQM1H-CPU51
CQM1H-CPU61
DM addresses from DM 6144 to DM 6568 make up the read-only area. Data
in the read-only area can be read from instructions (not overwritten) and it can
be read and overwritten from Programming Devices. Use the read-only area
to store data that you don't want to be changed from the program.
To prevent data from being overwritten by Programming Devices, turn ON pin
1 on the DIP switch on the front of the CPU Unit.
When a Controller Link Unit or Serial Communications Board is being used,
part of the read-only area is used for the Controller Link parameters/routing
table or Serial Communications Board settings, as shown in the following
table.
Name
Controller Link DM
parameters area
Routing table area
Serial Communications
Board settings
Note Data cannot be overwritten from Programming Devices when pin 1 on the DIP
switch on the front of the CPU Unit is ON.
The CPU Unit automatically records the error code and date/time of up to 10
errors (fatal and non-fatal) in the error log area.
Access from instructions
Read
YES
Name
Range Access from
instructions
Read
DM 0000 to YES
DM 3071
DM 0000 to
DM 6143
Range Access from
instructions
Read
DM 6400 to YES
DM 6409
DM 6450 to
DM 6499
DM 6550 to
DM 6559
Access from Programming Devices
Write
No YES
Section 3-9
Range
DM 6569 to DM 6599
DM 6600 to DM 6655
Access from
Programming Devices
Write Read
YES YES YES
Access from
Programming Devices
Write Read
No YES YES
(See note.)
Read Write
No
Write
Write
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