Omron CJ1W-CT021 Operation Manual page 26

Basic Configuration
I/O Connection Methods
6
Rack.
No external interrupt tasks can be activated in CJ1-H or CJ1M CPU Units if the
CJ1W-CT021 High-speed Counter Unit is in any other position (i.e., 6th Unit posi-
tion or further away from the CJ1-H CPU Unit, or 4th Unit position or further away
from the CJ1M CPU Unit), or if it is on a CJ-series Expansion Rack.
The maximum number of CJ1W-CT021 High-speed Counter Units that can be
mounted to a CJ CPU Rack or CJ Expansion Rack is equal to the number of slots
of the Rack. In a configuration with multiple Racks the maximum number of CJ1W-
CT021 High-speed Counter Units is limited to 24 because the Unit is allocated 40
CIO-words and 400 DM-words in the Special I/O Unit Area.
Furthermore, the number of High-speed Counter Units that can be mounted to
one Rack (i.e., a CPU Rack or Expansion Rack) depends on the maximum supply
current from the Power Supply Unit that supplies the Rack and the current con-
sumption of other Units on the Rack.
To connect the In- and Output signal wires to the Unit two methods are available:
1. Directly connecting the wires by soldering them to the external connector.
2. Indirectly connecting the wires by connecting them to screw terminals on a Ter-
minal Block Unit. The Omron Terminal Block Unit (XW2B-40G4 or XW2B-
40G5) is connected to the Unit via standard available Omron flat-cables
(XW2Z-xxxB).
Refer to 2-3-2 "Connector Wiring Methods" for more details.
Section 1-2