Omron CP1L - 12-2007, Руководство по эксплуатации

Страница: 174 / 673

141
Data Memory Area (D)
Section 4-10
4-10 Data Memory Area (D)
CPU Units with 30 or 40 I/O points: D0 to D32767
CPU Units with 14 or 20 I/O points: D0 to D9999 and D32000 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).
Forcing Bit Status Bits in the DM Area cannot be force-set or force-reset.
Indirect Addressing 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 (D0 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 (D0 to D09999) can be indirectly
addressed with BCD values 0000 to 9999.
Note (1) If an address between D10000 and D31999 is specified as an operand
for a CPU Unit with 14 or 20 I/O Points, an illegal area access error will
occur.
D32200
D32000
D32399
D9999
D0
D32199
D32399
D32200
D32199
D32767
D32400
D0
D32767
D32400
D10000
D31999
CPU Unit with 30 or 40 I/O Points
CPU Unit with 14 or 20 I/O Points
DM Fixed Allocation
Words for Modbus-RTU
Easy Master
DM Fixed Allocation
Words for Modbus-RTU
Easy Master
Do not use.
@D100
D256 0100
▲
Address actually used.
*
D100 D100
0100
▲
Address actually used.