DM Memory Area ???

[hand_drake]

Hi,
I have difficulties with reading someone's program.
Can sombebody explain what is: DM 6210, 6211, 6212?

Thank you for answering.

[luke12faulin]

Data Memory (DM) Area (Referee from OMRON CS1 Manual)

The DM Area contains 32,768 words with addresses ranging from D00000 to
D32767. This data area is used for general data storage and manipulation
and is accessible only by word.
Data in the DM Area is retained when the PLC’s power is cycled or the PLC’s
operating mode is changed from PROGRAM mode to RUN/MONITOR mode
or vice-versa.
Although bits in the DM Area cannot be accessed directly, the status of these
bits can be accessed with the BIT TEST instructions, TST(350) and
TSTN(351).

Bits in the DM Area cannot be force-set or force-reset

Words in the DM Area can be indirectly addressed in two ways: binary-mode
and BCD-mode

Binary-mode Addressing (@D)
When a “@” character is input before a DM address, the content of that DM
word is treated as binary and the instruction will operate on the DM word at
that binary address. The entire DM Area (D00000 to D32767) can be indirectly
addressed with hexadecimal values 0000 to 7FFF.

BCD-mode Addressing (*D)
When a “*” character is input before a DM address, the content of that DM
word is treated as BCD and the instruction will operate on the DM word at that
BCD address. Only part of the DM Area (D00000 to D09999) can be indirectly
addressed with BCD values 0000 to 9999.

Parts of the DM Area are allocated to Special I/O Units, CPU Bus Units, and
Inner Boards for functions such as initial Unit settings. The timing for data
transfers is different for these Units, but may occur at any of the three following
times.
1. Transfer data when the PLC’s power is turned on or the Unit is restarted.
2. Transfer data once each cycle.
3. Transfer data when required.
Refer to the Unit’s Operation Manual for details on data transfer timing.

Special I/O Units (D20000 to D29599)
Each Special I/O Unit is allocated 100 words (based on unit numbers 0 to 95).
Refer to the Unit’s Operation Manual for details on the function of these
words.

CPU Bus Units (D30000 to D31599)
Each CPU Bus Unit is allocated 100 words (based on unit numbers 0 to F).
Refer to the Unit’s Operation Manual for details on the function of these
words. With some CPU Bus Units such as Ethernet Units, initial settings must
be registered in the CPU Unit’s Parameter Area; this data can be registered
with a Programming Device other than a Programming Console.

Inner Board (D32000 to D32099)
The Inner Board is allocated 100 words. Refer to the Board’s Operation Manual
for details on the function of these words.