I/O Refreshing - Omron CJ2 CPU UNIT SOFTWARE User Manual

3 CPU Unit Operation

I/O Refreshing

The I/O Unit processing time depends on the type and number of Configuration Units that are used in
the PLC. The processing time for each Unit is constant.
It is possible to shorten the processing time by stopping cyclic I/O refreshing for Special I/O Units. To
stop I/O refreshing for Special I/O Units, set the parameter on the SIOU Refresh Tab Page in the CX-
Programmer. The following table lists the refresh processing for the PLC Units.
Basic I/O Units
Spe- Words allocated in CIO Area
cial I/O
Units
Unit-spe-
cific data
CPU Words allocated in CIO Area
Bus
Words allocated in DM Area
Units
Unit-spe-
cific data
(Refer to
the right.)
* Supported only by the CJ2H-CPU6@-EIP and CJ2M-CPU3@. The EtherNet/IP port built into the CJ2H-CPU6@-
EIP provides the same performance and functions as a CJ1W-EIP21 EtherNet/IP Unit. The EtherNet/IP port built
into the CJ2M-CPU3@ provides very different performance. Refer to the EtherNet/IP Unit Operation Manual (Cat.
No. W465) for details.
Additional Information
It is possible to exchange data with the Units when instructions are executed rather than during
the normal I/O refresh period. This is called immediate refreshing. Immediate refreshing is possi-
ble by attaching an exclamation mark (!) to some instructions, or by using the IORF(097),
FIORF(225), and DLNK(226) instructions.
The following instructions can be used to increase the speed of data exchange with certain Spe-
cial I/O Units or CPU Bus Units by using direct processing. Refer to the Instructions Reference
Manual (Cat. No. W474) for details.
• ANALOG INPUT DIRECT CONVERSION (AIDC(216)) (for CJ1W-AD042 High-speed Analog
Input Unit)
• ANALOG OUTPUT DIRECT CONVERSION (AODC(217)) (for CJ1W-DA042V High-speed
Analog Output Unit)
• DIRECT TRANSMIT VIA SERIAL COMMUNICATIONS UNIT/SERIAL PORT (DTXDU(262))
(CJ1W-SCU@2 only)
• DIRECT RECEIVE VIA SERIAL COMMUNICATIONS UNIT/SERIAL PORT (DRXDU(261))
(CJ1W-SCU@2 only)
• PCU HIGH-SPEED POSITIONING (NCDMV(218)) (CJ1W-NC@@4 and CJ1W-NC@ only)
• PCU POSITIONING TRIGGER (NCDTR(219)) (CJ1W-NC@81 only)
*1 These instructions are supported only by the CJ2H-CPU6@(-EIP) (unit version 1.1 or later) and CJ2M
CPU Units.
*2 Supported only by the CJ2H-CPU6@(-EIP) with unit version 1.3 or later and CJ2M CPU Units.
3-6
Units Maximum data exchange
Depends on the Unit.
10 words/Unit (Depends on the
Unit.)
CompoBus/S Master Unit Depends on the Unit.
25 words/Unit
100 words/Unit
* Depends on the EtherNet/IP
Built-in EtherNet/IP port
functions that are used.
EtherNet/IP Unit
Controller Link Unit and Depends on the Unit.
SYSMAC LINK Unit
DeviceNet Unit Depends on the Unit.
Serial Communications Depends on the protocol mac-
Unit ros.
Ethernet Unit Depends on the Unit.
*1
*1
*1
*1
Data exchange area
I/O Bit Area
Special I/O Unit Area
Words set for remote I/O communications
CPU Bus Unit Area
CPU Bus Unit words
Tag Data Link Area
Words set for data links (for either fixed or
user-set allocations)
Words set for remote I/O communications
(for either fixed or user-set allocations)
Communications data set for protocol
macros
Communications data for socket services
initiated by specific control bit operations.
*2
CJ2 CPU Unit Software User's Manual
*2