Omron CJ1W-DRM21 - Fixed Allocations; Allocated Words

5-7
5 Remote I/O Slave Communications
CJ-series DeviceNet Units Operation Manual for NJ-series CPU Unit(W497)
5-2 Fixed Allocations
5
5-2-1 Allocated Words
5-2 Fixed Allocations
If fixed allocation is used, allocated words are in the following I/O (CIO) area in the memory used for CJ-
series Unit. You can select words from one of three fixed allocations areas. Use
*_Sw2SlavFixAloc1Cmd to *_Sw2SlavFixAloc3Cmd (Slave Fixed Allocation Setting 1 to 3 Switch) to
select the allocation area.
Each area is comprised of an OUT area that is used to write data to the master IN area and an IN area
that is used for inputs from the master OUT area in remote I/O communications.
To access the following areas from the user program, user-defined variables that specify the AT specifi-
cation of these areas need to be defined.
You can include a maximum of 3 CJ-series DeviceNet Units as slaves in a single NJ-series CPU Unit
because the three allocation areas above are set individually for fixed allocations. The default setting is
fixed allocation area 1.
z Step 1: Set the CPU Unit to PROGRAM Mode.
z Step 2: Stop Slave Communications
If the Unit already functions as a Slave Unit, change *_Sw2SlavDsblCmd (Slave Stop Switch) to
TRUE to stop slave communications. This step is not necessary if slave communications are
stopped.
z Step 3: Select a Fixed Allocation Area
Change *_Sw2SlavFixAloc1Cmd to *_ Sw2SlavFixAloc3Cmd (Slave Fixed Allocation Setting 1 to 3
Switch) to TRUE to select a fixed allocations area between 1 and 3.
One word is allocated for the output (OUT) area from the Slave Unit to the CPU Unit and another
word is allocated for the input (IN) area from the CPU Unit to the Slave Unit in the memory used for
CJ-series Unit, as shown below.
5-2-1 Allocated Words
Area OUT area
(master to slave)
IN area
(slave to master)
Selection method
Fixed allocation area 1 CIO 3370 CIO 3270 Change *_Sw2SlavFixAloc1Cmd
(Slave Fixed Allocation Setting 1
Switch) to TRUE.
Fixed allocation area 2 CIO 3570 CIO 3470 Change *_Sw2SlavFixAloc2Cmd
(Slave Fixed Allocation Setting 2
Switch) to TRUE.
Fixed allocation area 3 CIO 3770 CIO 3670 Change *_Sw2SlavFixAloc3Cmd
(Slave Fixed Allocation Setting 3
Switch) to TRUE.
Allocation Procedures