Number Of Communication Data; Deal With 16 Bits Data - Mitsubishi Electric MELSEC FX Series User Manual

FX communication
9.3

Number of Communication Data

9.3.1

Deal with 16 bits Data

When M8161 is set to OFF (M8161 is shared by an ASCII instruction, a HEX instruction and a
CCD instruction.)
OFF during RUN
M8000
M8161
X010
FNC 80
RS
Send data
(Programmdble
controller →
External
equipment)
Receive data
(External
→
equipment
Programmdble
controller)
1 ) Send data and remaining number of send data
Send data SD (TXD)
Remaining number
of send data D8122
2 ) Receive data and number of receive data
Receive data RD (RXD)
Number of receive data
D8123
OFF
16-bit mode
S· D·
m
D200 K 4 D500
STX D200 lower D200 upper D201 lower D201 upper
Header
Head address specified by
Send byte count
specified by "m"
STX D500 lower D500 upper D501 lower D501 upper D502 lower D502 upper
Header
Head address specified by
It does not exceed the upper limit number
of receive data points (byte count)
specified by "n".
Receive is completed when the terminator
(ETX) or "n" points are received.
4
3
2
1
3
2
1
0
Upper 8 bits
16-bit data is divided into the
lower 8 bits and the upper 8
bits, then sent or received.
n
K 10
ETX
Terminator
S ·
D·
0
6
The number of receive
5
data is also reset when
4
the receive completion
flag M8123 is reset.
RS instruction 9
16-bit data
Lower 8 bits
ETX
Terminator
9-13
9