D-72
FX Series PLC User's Manual - Data Communication Edition
Computer Link
7 Commands
7.13 On-demand Function
7.13.3 On-demand function specification method and specification examples
This subsection explains the on-demand function specification method and specification examples.
When using ch2 in an FX
3U or FX3UC Series PLC, exchange special auxiliary relays (M) and special data
registers (D) according to the table below.
*1. FX
0N, FX1S, FX1N and FX1NC PLCs do not support this device.
1. Specification method
The specification method in the control procedure format 1 is shown below:
1) Specify the data quantity specification range while satisfying the following condition:
- Amount of data ≤ 40H (= 64 in decimal)
2) The PLC adds "FE" as the PLC number.
3) Express the station number, PLC number, number of device points and sum check code in hexadecimal.
All PLCs except FX3U and FX3UC PLCs
FX
3U and FX3UC PLCs (ch1)
FX3U and FX3UC PLCs (ch2)
M8127
*1
↔
M8427
M8128 M8428
M8129 M8429
D8127 D8427
D8128 D8428
PLC
On-demand send processing
M8127
Writes data to be sent and
amount of data to be sent.
ON
S
T
X
Data to be
sent
Added by PLC
E
T
X
OFF
Write the head device number (data register)
storing the data to be sent to the special data
register D8127.
Write the amount of data to the special data
register D8218.
Computer side
PLC side
PLC No.
Station
No.
Sum check
code