Control Procedures In On-Demand Function - Mitsubishi Electric FX3U-232-BD User Manual

FX Series PLC User's Manual - Data Communication Edition
Computer Link

7.13.2 Control procedures in on-demand function

This subsection explains the control procedures for the on-demand function.
When using ch2 in an FX
special data registers (D) according to the table below.
All PLCs except FX
FX , FX , FX
3G 3GC
*1. FX , FX
0N
1) Control procedure in the PLC
Sending of on-demand data
Checks unit (word or byte) of
Writes data to be sent to data
Resets on-demand error
Starts on-demand function
Checks for sending error
When there
is error
D-80
, FX , FX
3G 3GC
, FX , FX and FX
3G 3GC 3U 3UC
and FX PLCs (ch1)
3U 3UC
*1
M8127
M8128
M8129
D8127
D8128
, FX and FX PLCs do not support this device.
1S 1N 1NC
data to be sent
registers
When there is
no error
Sending is completed
or FX Series PLC, exchange special auxiliary relays (M) and
3U 3UC
PLCs
FX , FX
3G

It is checked whether M8129 is ON or OFF.
........
ON: Unit = byte (8-bit)
OFF: Unit = word (16-bit)
Data to be sent is written to data registers.
........
........ The on-demand error flag M8128 turns OFF.
(While M8128 is ON, the on-demand function is disabled.)
........ The head device (data register) number storing the on-
demand data is written to D8127, and the amount of data is
written to D8128.
When a request is accepted, M8127 is set to ON.
When sending is complete, M8127 turns OFF.
If the on-demand error flag M8128 is ON, it means that data
........
was not sent due to an error in the specified value to be sent.
7.13 On-demand Function
, FX and FX PLCs (ch2)
3GC 3U 3UC
M8427
M8428
M8429
D8427
D8428
7 Commands