Installation; System Configuration Precautions; Installing Units - Omron CJ1W-CT021 Operation Manual

Installation

2-2

Installation

2-2-1

System Configuration Precautions

2-2-2

Installing Units

!Caution
!Caution
30
Switch Machine
Setting Number
94 Cannot be
set
95 Cannot be
set
Note 1. If two or more Special I/O Units are assigned the same Machine Number, a fatal
error "Unit No. Duplication Error" (in the PLC-CPU) will be generated (A40113
will turn ON) and the PLC will not operate.
2. The High-speed Counter Unit is allocated the words for 4 Units. If you use Spe-
cial I/O Units that are allocated more than 100 DM-words and 10 CIO-words,
like the CJ1W-CT021 High-speed Counter Unit, you should make sure that no
memory overlapping occurs. If the Machine Number for the High-speed Coun-
ter Unit is set to 'n' the Machine Number of the Special I/O Unit should be set
to 'n+4', in order to avoid memory overlapping. In case two or more Special I/O
Units have set Machine Numbers that cause an overlapping of allocated mem-
ory a fatal error "Unit No. Duplication Error" (in the PLC-CPU) will be generated
(A40113 will turn ON) and the PLC will not operate.
3. Besides the memory that is allocated to the High-speed Counter Unit in the
Special I/O Unit DM Area, for every Counter additional memory can be allo-
cated in DM/EM. This extra allocated amount of memory is used to make the
Counter Specific Settings related to Range or Comparison Mode. Memory is
allocated by specifying an Indirect Address for every Counter in the Special I/
O Unit DM Area. For details about Indirect Addressing refer to 4-2-2 "Indirect
Addressing".
Up to 24 Units can be connected for each PLC (CPU Unit), including up to 10 on
each Rack (CPU Rack and Expansion Racks).
Note The Unit must be mounted to one of the five positions immediately to the right of
the CJ1-H CPU Unit (when facing the PLC) to generate interrupts to the CPU
Unit to execute external interrupt tasks. Interrupts are not supported from any
other location on the CPU Rack and are not supported at all from Expansion
Rack. They are also not supported by CJ1 CPU Units.
Leave the protective label on top of the Unit as long as the Unit is not mounted
and wired completely, in order to prevent wire clippings or other materials from
getting inside the Unit. When the mounting and wiring has been completed, the
label must be removed to allow air circulation and heat radiation.
Be sure to turn OFF the power supply to the PLC before installing or removing
Units or connecting or disconnecting connectors.
I/O Refresh Data Area
Addresses
Not Applicable
Not Applicable
Section 2-2
Special I/O Unit DM
Area Addresses
Not Applicable
Not Applicable