Cpu Bus Unit Area - Omron CS1D DUPLEX SYSTEM - 10-2009 Operation Manual

CPU Bus Unit Area

Link Area Initialization
1,2,3...
IOM Hold Bit Operation
Forcing Bit Status
8-6

CPU Bus Unit Area

268
A data link automatically (independently of the program) shares data with Link
Areas in other CPU Units in the network through a Controller Link Unit
mounted to the PLC's CPU Rack.
Data links can be generated automatically (using the same number of words
for each node) or manually. When a user defines the data link manually, he
can assign any number of words to each node and make nodes receive-only
or transmit-only. Refer to the Controller Link Units Operation Manual (W309)
for more details.
Words in the Link Area can be used in the program when LR is not set as the
data link area for automatic allocation for Controller Link Networks and PLC
Links are not used.
Controller
Link Unit
CPU Unit
The contents of the Link Area 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.
2. The PLC's power supply is cycled and the IOM Hold Bit is OFF or not pro-
tected in the PLC Setup.
3. The Link Area is cleared from a Programming Device.
4. PLC operation is stopped when a fatal error other than an FALS(007) error
occurs. (The contents of the Link Area will be retained if FALS(007) is ex-
ecuted.)
By default, the Data Link Area is cleared when power is interrupted or the
CPU Unit is restarted.
If the IOM Hold BIt (A50012) is ON, the contents of the Link Area won't be
cleared when a fatal error occurs or the operating mode is changed from
PROGRAM mode to RUN/MONITOR mode or vice-versa.
If the IOM Hold BIt (A50012) is ON and the PLC Setup's "IOM Hold Bit Status
at Startup" setting is set to protect the IOM Hold Bit, the contents of the Link
Area won't be cleared when the PLC's power supply is cycled.
Bits in the Link Area can be force-set and force-reset.
The CPU Bus Unit Area contains 400 words with addresses ranging from
CIO 1500 to CIO 1899. Words in the CPU Bus Unit Area can be allocated to
CPU Bus Units to transfer data such as the operating status of the Unit. Each
Unit is allocated 25 words based on the Unit's unit number setting.
Link Areas
Controller
Link Unit CPU Unit
Controller Link Network
Section 8-6
Controller
Link Unit
CPU Unit