9.
COMMUNICATIONS IN THE NO-PROTOCOL MODE
MELSEC-A
(2)
Data sending procedure
Computer
I-word
data
is
expressed
in 2 characters
~
~
7
1
~
4
Data
to be transmtted
-
L , H ; L , H \
Send
complete
XnO
Send request
Y(.+qO
-
Turn ONIOFF by program
PC
CPU
(Send data
length
(Program)
Send data)
9
(1) An error occurs if the send data length is greater than the send area,
or equal to "0". In this case, "1" is written as transmission error
information to the most significant bit (bit 15) of address 101 H (error
LED display area) in the special application memory area.
(See
Section 7.3.1 .)
(2) The send data length written to the head address of the send area
is not transmitted.