Precautions When Using Iowr; Iowr Program Example - Omron C200HW Operation Manual

Writing Data with IOWR

5-4-4 Precautions when Using IOWR

5-4-5 IOWR Program Example

IOWR is an improvised instruction which transfers all data with a single instruc-
tion. It increases the transfer time for the data as well as the cycle time for the
ladder program. The monitoring time for the cycle time should be adjusted as
required.
The transfer time is influenced by such factors as the model of the Program-
mable Controller being used, the ladder program, and the status of the Position
Control Unit, and cannot be calculated easily. Refer to Appendix A Data Calcula-
tion Standards to transfer positioning sequences using a C200HX and a
C200HW-NC413. It can be used as a model for setting cycle time monitoring
time.
Using IOWR, a maximum of 128 words of data in consecutive addresses can be
transferred at one time.
When using IOWR, be sure to transfer data in complete units, and do not start or
end transfer in the middle of data. For example, with X-axis sequence #0, the
data unit becomes three words consisting of addresses from 1000 to 1002. If the
transfer is started or ended part-way through, ER Flag 25503 will be turned ON.
When transferring the origin search high speed and origin search proximity
speed settings, be sure to transfer both settings together. It is not possible to
transfer only one of these settings.
Note Depending on the execution timing of the IOWR instruction, it is possible that
errors generated as a result of data check at the time of transfer may not be
reflected at the CPU Unit. (Refer to 5-1 Transferring and Saving Data.)
A sample program is provided below for writing the indicated speed data to the
Position Control Unit. The beginning word address of the transfer data is to be
DM 0500, and the other settings are as indicated. The data will be transferred to
the Position Control Unit designated as Unit No. 2.
Data
Speed #0
Speed #1
Unit No.
Data transfer
Address (transfer
destination)
1300 0500
1301 0501
Position Control Unit (NC413, Unit No. 2)
Data area
Section
DM (transfer Setting
source)
1000
5500
Speed #0
Speed #1
5-4
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