Data Registers - Omron CS1D DUPLEX SYSTEM - 10-2009 Operation Manual

Data Registers

Sharing Index Registers

8-18 Data Registers

Examples
Range of Values
Data Register Initialization
1,2,3...
This setting can be made from the CX-Programmer.
To share Index Registers among tasks, remove the check from (deselect) the
Use IRs/DRs independently per task Option.
The sixteen Data Registers (DR0 to DR15) are used to offset the PLC mem-
ory addresses in Index Registers when addressing words indirectly.
The value in a Data Register can be added to the PLC memory address in an
Index Register to specify the absolute memory address of a bit or word in I/O
memory. Data Registers contain signed binary data, so the content of an
Index Register can be offset to a lower or higher address.
Bits in Data Registers cannot be force-set or force-reset.
Regular instructions can be used to store data in Data Registers.
Set to a base value
with MOVR(560) or
MOVRW(561).
Set with a regular
instruction.
The following examples show how Data Registers are used to offset the PLC
memory addresses in Index Registers.
LD DR0 ,IR0
MOV(021) #0001 DR0 ,IR1
The contents of data registers are treated as signed binary data and thus
have a range of –32,768 to 32,767.
Hexadecimal content
8000 to FFFF –32,768 to –1
0000 to 7FFF 0 to 32,767
The Data Registers will be cleared in the following cases:
1. The operating mode is changed from PROGRAM mode to RUN/MONITOR
mode or vice-versa and the IOM Hold Bit is OFF.
I/O Memory
Pointer
Adds the contents of DR0 to the contents
of IR0 and loads the bit at that PLC mem-
ory address.
Adds the contents of DR0 to the contents
of IR1 and writes #0001 to that PLC
memory address.
Decimal equivalent
Section 8-18
317