Mitsubishi Electric FX3U-232-BD User Manual page 293

FX Series PLC User's Manual - Data Communication Edition
Computer Link
3. PLC number
The PLC number is used to identify a PLC to be accessed when computer link is combined with the
MELSECNET (II) or MELSECNET/B in A Series PLCs. The PLC number of each FX Series PLC is fixed to
"FFH", and converted into two-digit ASCII code.
When the on-demand function is used, however, the PLC number is automatically changed to "FEH" by the
PLC.
For the PLC number of an A Series PLC used together with the MELSECNET (II) or MELSECNET/B, refer to
the respective A Series PLC manual.
4. Command
A command specifies the contents of access executed by the computer to a PLC.
A command is converted into a two-digit ASCII code.
5. Message waiting time
The message waiting time should be specified because some computers require more time before receiving
additional data. Set the waiting time according to the specifications of each computer.
Set the waiting time within the range from 0 to 150 ms in 10-ms
ranging from "0H (0)" to "FH (15)" is converted into a one-digit ASCII code.
When executing communication using the 485PC-IF in a 1-to-N system adopting the one-pair wiring, make
sure to set the message waiting time to 70 ms (7) or more. When the scan time of a PLC in the system
exceeds 70 ms, set the message waiting time to the maximum scan time or higher.
Example: When the message waiting time is set to 100 ms
Computer side
PLC side
FX , FX
2N
FX (FX), FX
2
Message waiting time (100 ms)
"A"
Sending is started 100 ms or later.
PLC
FX , FX
3U 3UC
, FX , FX , FX
2NC 3S 3G 3GC
, FX , FX , FX , FX
2C 0N 1S 1N 1NC
6 Control Procedures and Setting Methods
For an explanation of commands, refer to Chapter 7.
. 10 ms is handled as "1H", and a value
units
The waiting time should be the interval
times in the following table or more.
Interval times
300 s
100 s
two scan times
6.4 Basic Formats of Dedicated Protocol
D-51
A
B
C
D
E
F
G
H
I
Apx.A