Description of Operation
Section
3-2
112
Note 2
Field Terminals that do not undergo writing by the Loop Control Unit
Model
Function block
name
Target Analog
Input/Output Unit
Internal writing by
Loop Control Unit
Writing of
analog
values
551
AI 8-point
Terminal (AD003)
C200H-AD003
561
AI 4-point
Terminal
(PTS01/02/03,
PDC01, PTW01)
CS1W-PTS01
(isolated-type
thermocouple
input), CS1W-
PTS02/03
(isolated-type
temperature-
resistance
thermometer),
CS1W-PDC01
(isolated-type
analog input),
CS1W-PTW01
(2-wire
transmitter input)
562
AI 4-point
Terminal
(PPS01)
CS1W-PPS01
(isolated-type
pulse input)
564
AI 8-point
Terminal
(PTR01/02)
CS1W-PTR01
(Power
Transducer Input
Unit), CS1W-
PTR02 (analog
input 100 mV)
584
AI 8-point
Terminal (AD081)
CS1W-AD081
586
AI 4-point
Terminal (AD041)
CS1W-AD041
None
None
When Analog Output Units C200H-DA003/004, CS1W-DA08V/C or
CS1W-DA041 and Analog Input/Output Unit C200H-MAD01 or CS1W-
MAD44 are used
When the operation mode of the CPU Unit changes from RUN or MONITOR
to PROGRAM, the Conversion Enable flag of the Analog Output Unit and the
Analog Input/Output Unit is turned OFF from the CPU Unit, and the output
hold function holds analog output values at the previous value, minimum
value or maximum value.
The Loop Control Unit forcibly turns this Conversion Enable flag ON when the
Unit is in use.
However, when the CPU Unit changes to the PROGRAM mode, the
Conversion Enable flag momentarily (operation cycle of Loop Control Unit)
turns OFF, and as a result the analog output value is momentarily switched to
the momentary output hold value.
To prevent the analog output value from being switched to the momentary
output hold value when the CPU Unit changes to the PROGRAM mode, set
the I/O Memory Hold flag (A50012) of the CPU Unit to ON, and set "Hold
ON/OFF of I/O Memory Hold flag at power ON" to ON in the PC system
settings.