User`s manual

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MELSEC-Q
3 SPECIFICATIONS
3.2.2 Analog output HOLD/CLEAR function
Whether the output analog value will be retained or cleared according to the PLC CPU
operating status (RUN, STOP, and Stop error) can be set using the intelligent function
module switch (see Section 4.5).
Table 3.4 lists available analog output status based on the combinations of D/A
conversion enable/disable and CH
output enable/disable.
Perform settings according to the system application.
Table 3.4 Analog output status combination list
D/A conversion enable/disable
Setting (buffer memory address 0: Un\G0)
Enable Disable
CH output enable/disable flags (Y1 to Y8) Enable Disable Enable or disable
Setting
combination
execution
status
HOLD/CLEAR setting HOLD CLEAR HOLD or CLEAR HOLD or CLEAR
Analog output status when PLC CPU is running
Outputs the analog value of the
D/A converted digital value.
Offset 0 V/0 mA
Analog output status when PLC CPU is stopped Hold Offset Offset 0 V/0 mA
Analog output status when a PLC CPU stop error occurs Hold Offset Offset 0 V/0 mA
Analog output status when a watchdog timer
1
error occurs
in D/A converter module
0 V/0 mA 0 V/0 mA 0 V/0 mA 0 V/0 mA
1 This occurs when program operations are not completed within the scheduled time due to a hardware
problem of the D/A converter module. When a watchdog timer error occurs, module READY (X0) turns
OFF and the D/A converter module RUN LED turns off.
POINT
(1) Design the system so that the D/A conversion enable/disable setting (buffer
memory address 0: Un\G0) changes to "Enable" after the external power (see
Section 4.3) is supplied.
Analog output may not properly be performed if the external power is not at the
specified voltage.
(2) The following conditions should be satisfied when the analog output
HOLD/CLEAR function is used on a MELSECNET/H remote I/O station.
• The master module of function version D or later and the remote I/O
module of function version D or later are required.
• Validate the station unit block guarantee of the send side cyclic data.
For the station unit block guarantee of the cyclic data, refer to the Q
Corresponding MELSECNET/H Network System Reference Manual (Remote
I/O Network).