NAiS FP Series User Manual page 203

Communication Function 2 General - purpose Serial Communication
When sending data:
Relationship between the various flags "Reception done flag and Transmission done
flag" and the F159 (MTRN) instruction
Transmitted data
on
Transmission
done flag
"R9039 or R9049"
off
F159 (MTRN) on
instruction
execution
off
Transmission buffer
Number of bytes not
yet transmitted
Figure 199: FPΣ Flag operation when sending data (STX and ETX setting)
Start code (STX) and end code (ETX) are automatically added to the data being
transmitted, and the data is transmitted to an external device.
When the F159 (MTRN) instruction is executed, the transmission done flag "R9039 or
R9049" go off.
Duplex transmission is disabled while the F159 (MTRN) instruction is being executed.
Check the transmission done flag "R9039 or R9049".
9 - 36
a
STX b ETX
Transmission
Duplex transmission
disabled while F159
(MTRN) instruction
is being executed
a a a a
b
b
b b
<2> <1> <0> <0>
c
STX d e
Transmission
c
c c
c
d
d
d
d
e e
e e
<3> <2> <1> <0>
* : Transmission point
FPΣ
ETX
c
d
e
<0>