Panasonic FP0 - If Yes Has Been Set for the Start and Terminal Codes; (Start Code: STX, Terminal Code: ETX)

General−use Serial CommunicationsFP0
10 − 9
10.3 Operations When Using General−use Serial Communication
When the F144 (TRNS) instruction is executed, the number of bytes received is cleared,
and the address (write pointer) returns to the initial address in the reception buffer.
Reception stops if the error flag (R9037) goes on. To resume reception, execute the
F144 (TRNS) instruction. This turns off the error flag, and transmits both actual and
empty data.
10.3.2 If “Y es” has been Set for the Start and T erminal Codes
(Start Code: STX, T erminal Code: ETX)
When receiving data
Number of bytes
received is cleared
when F144 (TRNS)
instruction is ex-
ecuted.
A
B
C
STX
D H ETX
A A
B B
C
A
B
C
A
E
C
G
E
C
H
E
C
H
<1> <2> <3> <0> <0> <1> <1>
E ETX F G STX
The reception com-
pleted flag is
turned off by ex-
ecuting the F144
(TRNS) instruction.
The reception
code is deleted
by the F144
(TRNS) instruc-
tion.
B
C
D
<1>
E
C
D
<2>
E
C
D
<2>
E
C
D
<0>
E
C
G
<1>
Number of
bytes received
is cleared when
start code is
received.
on
off
on
off
External
received
data
R9038
Reception com-
pleted flag
F144 (TRNS)
instruction
execution
Reception
buffer
Number of recep-
tion bytes
Stored
Write pointer
Cannot be
stored when
reception
completed
flag is on
Number of
bytes received
is cleared when
start code is
received.
The data is stored in the reception buffer in sequential order, but at the point at which
the start code is received, the number of bytes received is cleared, and the address
(write pointer) is returned to the initial address in the reception buffer.
When the F144 (TRNS) instruction is executed, the number of bytes received is cleared,
and the address (write pointer) is returned to the initial address in the reception buffer.
If there are two start codes, data following the later start code is overwritten and stored
in the reception buffer.
Reception is disabled while the reception completed flag (R9038) is on.
The reception completed flag (R9038) is turned off by the F144 (TRNS) instruction.
Because of this, if the F144 (TRNS) instruction is executed at the same time that the
terminal code is received, the reception completed flag will not be detected.