Mitsubishi Electric MELSEC-FX3S Series - Page 322

G-10
2 Specifications
2.3 D/A Conversion Time
FX 3S /FX 3G /FX 3GC /FX 3U /FX 3UC PLC User's Manual - Analog Control Edition
FX3G-1DA-BD (1-channel Analog Output)
2.3.2 For FX3G Series PLC
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."
FX 3G Series PLC
Sequence Program
END instruction
Board A
FX
3G -1DA-BD FX 3G -1DA-BD
/1ch
60 s
/1ch
60 s
Board B
D/A conversion
start command
D/A
conversion
D/A
conversion
Digital value
writing
Digital value
writing
D/A conversion
start command