Omron CJ1W-CT021 Operation Manual page 115

Overview
Special I/O Unit Area and
Special I/O Unit DM Area
Unit Status Data
Unit Configuration Data
The Special I/O Unit Area and the Special I/O Unit DM Area are allocated to the
Unit according to the Machine Number (=N) set. For the Special I/O Unit Area 40
CIO words are allocated and for the Special I/O Unit DM Area 400 DM words are
allocated. For more information on the exact memory location of the Special I/O
Unit and Special I/O Unit DM Areas and the Machine Numbers that can be set,
refer to 2-1-4 "Machine Number Switch".
The Special I/O Unit Area contains the status information of the High-speed Coun-
ter Unit in CIO and is divided in an area with output words and an area with input
words. Both areas are divided in three parts: a general part and two Counter spe-
cific parts, and these are updated cyclically every I/O refresh.
The Unit configuration data is located in the Special I/O Unit DM Area, which is
allocated to the High-speed Counter Unit, and the Range/Comparison Data. The
Mode for which the Unit is configured determines if you have to set Range or Com-
parison Data (refer to 3-5-1 "Range Mode" and 3-5-2 "Comparison Mode" for
more information). The location of the Range/Comparison Data is indicated by an
Indirect Address that you have to specify for every Counter (refer to 4-2-2 "Indirect
Addressing" for detailed information).
The Special I/O Unit DM Area contains the configuration settings of the High-
speed Counter Unit. It is divided in three parts: a general part and two Counter
specific parts. The general part contains the settings that are relevant for the
whole Unit and the Counter specific parts contain the settings that are relevant to
the specific Counters.
The Unit Configuration Data is transferred to the High-speed Counter Unit at
Power Up or after the Unit has been restarted (refer to 4-1-2 "Special I/O Units
Restart bits").
•
Note The Unit configuration data can also be transferred during actual operation of
the Unit, by issuing an IOWR-instruction (refer to 4-5-3-4 "(Re) Configure
Unit").
•
I/O Refresh will not occur while the Data Transfer Busy bit (CIO n+19, bit 02) is
ON. For example, the Counter Value will not be refreshed while the bit is ON.
Section 4-1
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