Initialization At Startup - Omron CP1L-EL20DR-D Operation Manual

CPU Unit Operation
IORF(097) Refreshing
Note
2-4-4

Initialization at Startup

Note
54
(4) Using instructions with the immediate refresh option, instruction execu-
tion time will be increased, increasing the overall cycle time. Be sure to
confirm that this will not adversely affect system operation.
When IORF(097) (I/O REFRESH) is executed, the I/O bits in the specified
range of words are refreshed. IORF(097) can be used for CP-series Expan-
sion Units and CP-series Expansion I/O Units.
IORF
St: Starting word
St E: End word
All the words from St to E, inclusive
E
are refreshed.
Example
IORF
Here, the four words from CIO 2
to CIO 5 are refreshed.
2
5
If high-speed response is required from input to output, execute IORF(097)
before and after the relevant instructions.
IORF(097) has a relatively long execution time which increases with the num-
ber of words being refreshed. Be sure to consider the affect of this time on the
overall cycle time. Refer to the CP Series Programmable Controllers Program-
ming Manual for instruction execution times.
The following initializing processes will be performed once each time the
power is turned ON.
• Confirm mounted Units and I/O allocations.
• Clear the non-holding areas of I/O memory according to the status of the
IOM Hold Bit. (See note 1.)
• Clear forced status according to the status of the Forced Status Hold Bit.
(See note 2.)
• Automatically transfer data from the Memory Cassette if one is mounted
and automatic transfer at startup is specified.
• Perform self-diagnosis (user memory check).
• Restore the user program. (See note 3.)
(1) The I/O memory is held or cleared according to the status of the IOM Host
Bit and the setting for IOM Hold Bit Status at Startup in the PLC Setup
(read only when power is turned ON).
Auxiliary bit
PLC Setup setting
IOM Hold Bit Status
at Startup
Note When the mode is changed between PROGRAMMING mode and
RUN or MONITOR mode, I/O memory initialization is according to
the status of the IOM Hold Bit at that time.
IOM Hold Bit (A500.12)
Clear (OFF)
Clear At power ON: Clear
(OFF) At mode change: Clear
Hold
(ON)
Section 2-4
Hold (ON)
At power ON: Clear
At mode change: Hold
At power ON: Hold
At mode change: Hold