Omron CX-PROCESS TOOL V5.2 - REV 10-2010 Operation Manual page 25

Safety Precautions
WARNING
!
WARNING
!
WARNING
!
WARNING
!
! Caution
Caution
!
Check the following items before starting Loop Controller operation:
Do not allow the area to which user link table data is written to overlap with any
other area used by the CPU Unit or other Units. If areas overlap, the system may
operate in an unexpected manner, which may result in injury.
When using a user link table to write bit data to I/O memory in the CPU Unit.
Never allow ladder programming or communications processes in the CPU Unit
to write to any bits in the words in which bits are written from a user link table.
Depending on the timing, any attempts to write to these words from ladder pro-
gramming or communications processes may be ignored. Example: If tag A in a
user link table writes to bit 00 of W000 and an OUT instruction in the ladder pro-
gram in the CPU Unit write to bit 01 of W000, the write from the ladder program
may be ignored.
Analog I/O Units used in combination with the Loop Controller must be mounted
correctly.
The unit number set on the front panel of the Analog I/O Unit must be the same
as the unit number set on the Field Terminal Function Block. If the unit numbers
are not the same, I/O (read/write) will be performed on the data for another Spe-
cial I/O Unit (i.e., the one whose unit number is set in the Field Terminal Function
Block).
The initial settings of the System Common Block in the Loop Controller must be
set correctly. In particular, make sure that words in the Data Memory used for the
Node Terminals in the CPU Unit controlling the Loop Controller are not used for
other applications on the PLC.
When writing data to the I/O memory in the CPU Unit with function blocks (e.g.,
using Send All Blocks, Expanded DO/AO Terminal to CPU Unit, or DO/AO Ter-
minal to CPU Unit), be sure that the words written to in I/O memory are not being
used for any other purpose. If I/O memory words are allocated to more than one
purpose, the PLC system may act unexpectedly and cause injury.
Always stop the operation of the LCBjj before converting any of the EM Area
to file memory. If any part of the EM Area that is being used by the LCBjj for
the HMI is converted to file memory during Board operation, the system may
operate in an unexpected fashion, which may result in injury.
Do not perform processing in such a way that the Loop Controller and CPU Unit
write to identical I/O memory words allocated to a contact output or analog
output of an external Unit. If the same words are written to, the externally
connected loads may act unexpectedly and cause injury.
When the calibration function is executed, the MV (manipulated variable) will
change due to changes in the PVs (present values) input to the control block.
Therefore, set pseudo-input values to confirm safety when the MW changes
before executing the calibration function. Devices may perform unexpected
operations, resulting in serious accidents.
Before transferring function block data (initial setting data or operation data) to
the Loop Controller, confirm that the destination for the data is correct and also
confirm the overall safety of the system (including the Loop Controller). Not do-
ing so may result in unexpected operation.
Before performing Validate Action, be sure to perform Compare on currently
opened function files and the Loop Controller's function block data. If there are
inconsistencies in the registered function blocks (block address vs. block mod-
el), it will not be possible to perform Validate Action correctly.
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