Mitsubishi Electric FX3G User Manual page 322

FX /FX /FX /FX /FX
3S 3G 3GC 3U
FX -1DA-BD (1-channel Analog Output)
3G
2.3.2 For FX Series PLC
3G
1. D/A conversion and special data register update timing
D/A conversion is performed at every scan time of the PLC.
During execution of the END instruction, the PLC writes the output setting data of the special data registers,
performs D/A conversion of the data, and updates the analog output data.
2. D/A conversion during PLC stop
If the output holding function cancellation setting is enabled by the special device, the offset value will be
output.
If the output holding function cancellation setting is disabled, the output at switching from RUN to STOP will
be latched.
Just after power-on, however, the offset value will be output until operation begins.
3. If two analog expansion boards are connected
During execution of the END instruction, data in all the connected boards will be subject to D/A conversion
and then output (in the order of board A → board B).
4. D/A conversion speed (data update time)
During execution of END instruction, the output setting digital data will be subject to D/A conversion which
takes 60 μs, after which the analog data will be output.
END instruction execution time will be "60 μs × number of connected board."
G-10
PLC User's Manual - Analog Control Edition
3UC
D/A conversion Digital value
start command writing
D/A
conversion
60 s
/1ch
FX -1DA-BD
3G
Board A
FX Series PLC
3G
Sequence Program
END instruction
D/A conversion
start command
D/A
conversion
60 s
/1ch
FX -1DA-BD
3G
Board B
2 Specifications
2.3 D/A Conversion Time
Digital value
writing