Panasonic FP0H User Manual page 67

 When sending data: The reception done flag, the transmission done flag, and the
F159 (MTRN) instruction are related as follows:
Send data
Transmission
done flag
R913B
Execute F159
(MTRN) instruction
Send buffer
Number of unsent bytes
• Header (STX) and terminator (ETX) are automatically added to send data that is transmitted
to an external device.
• When F159 (MTRN) is executed, the the transmission done flag R913B turns OFF.
• Duplex transmission is disabled while F159 (MTRN) is being executed. The transmission
done flag R913B must be observed.
 Special relays / special data registers
Reception done flag in general-purpose
communication
Transmission done flag in general-
purpose communication
(Note): The Nos. in brackets indicate devices that are compatible with existing FP-X / FPΣ.
7.3 Flag Operations in Transmission / Reception
a
ETX
STX b
Send
Duplex transmission is
disabled while MTRN is
being executed
a a a a
b b b b
<2> <1> <0> <0>
COM0
R9132 (R903E)
R9133 (R903F)
STX c d
Send
c c c
d d d
e e e
<3> <2> <1>
COM1
R913A (R9038) R9142 (R9048)
R913B (R9039) R9143 (R9049)
e ETX
ON
OFF
ON
OFF
c c
d d
e e
<0> <0>
COM2
7-9