NAiS FP Series, User Manual

Page: 181 / 326

FP
Σ
Communication Function 2 General-purpose Serial Communication
9 - 14
Explanation during reception
When the reception done flag R9038(R9048) is off, operation takes place as follows
when data is sent from an external device. (The R9038(R9048) is off during the first
scan after RUN).
1. Incoming data is stored in order from the lower-order byte of the
2nd-word area of the reception buffer.
A B
…
T U V (
CR
)
Beginning of reception
Received data
R9038(R9048)
Execution condition
R0
Reception
is possible
…
Reception is
possible
Reception
is not pos-
sible
Reopening
on
off
on
off
Execution of
F159(MTRN)
instruction
Header and terminator (Start and end codes) are not stored.
Figure 180: Explanation during reception
2. When the terminator (end code) is received, the reception done
flag “R9038(R9048)” turns on. Reception of any further data is
prohibited.
3. When an F159(MTRN) instruction is executed, the reception done
flag “R9038(R9048)” turns off, the number of received bytes is
cleared, and subsequent data is stored in order from the
lower-order byte.