Mitsubishi Electronics MELSEC-F Manuel D’Utilisation
L-8
2 Specifications
2.4 A/D Conversion Time
FX
3G
/FX
3U
/FX
3UC
PLC User's Manual - Analog Control Edition
FX
3U
-4AD-TC-ADP (4-channel Thermocouple Data Input)
2.4
A/D Conversion Time
This section describes the A/D conversion time.
2.4.1
When connected to a FX
3U
, FX
3UC
PLC
1. A/D conversion and special data register update timing
A/D conversion is performed at every scan time of the PLC.
During execution of END instruction, the PLC performs A/D conversion, reads out the A/D converted data,
and then writes the data in the special data registers.
During execution of END instruction, the PLC performs A/D conversion, reads out the A/D converted data,
and then writes the data in the special data registers.
2. A/D conversion during PLC stop
Even if the PLC is stopped, A/D conversion will be performed and the special data registers will be updated.
3. If two or more analog special adapters are connected
During execution of the END instruction, data will be read out from all the connected adapters (in the order of
1st adapter
1st adapter
→ 2nd adapter…4th adapter).
4. A/D conversion speed (data update time)
During execution of the END instruction, the A/D converted data of all 4 channels will be read out in 200
μs,
and the data read out will be written to the special data registers.
END instruction execution time will be "200
END instruction execution time will be "200
μs × number of connected adapters."
FX
3U
/FX
3UC
Series PLC
FX
3U
-4AD-TC-ADP
1st
FX
3U
-4AD-TC-ADP
n'th
A/D
conversion
200
μs/4ch
A/D
conversion
200
μs/4ch
Digital value reading
A/D conversion start
command
END instruction
Sequence
program
Digital value reading
A/D conversion start
command