Omron SYSMAC CS Series Operation Manual page 197

Exchanging Data Using SCADA and Other Software
!Caution Always stop the operation of the Loop Controller before converting any of the
!Caution Do not use battery-free operation for the CS1-H CPU Unit or the CPU Unit
!Caution Do not use the HMI function to write a value that is outside of the data range
Note
EM Area to file memory. If any part of the EM Area that is being used by the
Loop Controller for the HMI is converted to file memory during Loop Controller
operation, the system may operate in an unexpected manner, which may
result in injury. If a batch download or System Common Block download is
performed in this state (i.e., with EM Area converted to file memory), a
0x0A0D error (FINS response 0x110C) will occur, and the download will stop
before completion. When the power supply is turned ON again, A424.04
(Incompatible CPU Unit Error Flag) will turn ON to indicated a non-fatal Inner
Board error. Clear the EM Area file memory.
element of a Process-control CPU Unit or Loop-control CPU Unit when using
the HMI interface. If batteryfree operation is used for the CPU Unit or CPU
Unit element, the contents of the EM Area will not be stable when the power
supply is turned ON, possibly causing illegal values in the HMI data in the
Loop Controller.
shown in the ITEM list in the Function Block Reference Manual (Cat. No.
W407) to the receive area (CPU Unit to Loop Controller) in the EM Area. Writ-
ing an out-of-range value can result in unexpected operation by the controlled
machine or equipment.
1. Data values that are 8 digits long (such as accumulated values) are divided
into two 4-digit ITEMs. Consequently, 8-digit values are divided into two
words when they are stored in the EM area. (For example, the accumulat-
ed value of the batch flowrate capture is stored in words n+10 and n+11,
with the rightmost 4 digits in n+10 and the leftmost 4 digits in n+11.)
When reading and writing 8-digit values, observe the following precautions
and perform any required processing in the SCADA Software to verify that
the 8-digit data is correct.
a. Writing Data from SCADA Software to the EM Area's Reception Area
(CPU Unit → Loop Controller)
When ITEM data has been changed by internal Loop Controller pro-
cessing or changed directly by the CX-Process Tool or FINS command
(not through the EM area), the Loop Controller will write the new data
in the EM area's reception area.
If the same ITEM is overwritten from the SCADA Software, the write
processes may conflict. It is possible that the two adjacent 4-digit
ITEMs making up an 8-digit value (such as an accumulated value) will
not be consistent. (For example, it is possible that the ITEM containing
the leftmost 4 digits will contain data written from SCADA software and
the ITEM containing the rightmost 4 digits will contain data written from
the Loop Controller.)
To prevent 8-digit values, such as accumulated values, from being cor-
rupted when writing from the SCADA Software, read the ITEM data
from the 2 ITEMs immediately after they have been written and verify
that they contain the correct data. In the unlikely event that the 2 ITEMs
do not contain the correct data, write the data again.
b. Reading the EM Area's Send Area Data from SCADA Software
(Loop Controller → CPU Unit)
When an 8-digit value (such as an accumulated value) is being read
from the SCADA Software and being overwritten simultaneously from
the Loop Controller, it is possible that only one of the two ITEMs will
Section 3-4
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