Panasonic FP2 Series, Руководство пользователя

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FP2 Serial Data Unit
Communication with External Devices
4 − 20
4.5 Data Sent and Received with the Serial Data Unit
4.5 Data Sent and Received with the Serial Data Unit
The three precautions should be observed when accessing the shared memory of the
serial data unit.
•
Sent and received data stored in the shared memory is ASCII code
data. However, the codes set as the start and end codes cannot be
used for any purpose other than as start and end codes.
•
If “Yes” is selected for “start code” in the transmission format
settings, the STX (H02) must always be added at the beginning of
the data being sent.
•
The end code specified in the transmission format must always be
added at the end of the data being sent.
When sending data:
The data written to the sent buffer of the shared memory is sent just as it is. Also, data
is written to the shared memory in 1 − byte units, starting from the lowest byte of the word
data.
Example:
When the data “12345” is sent as an ASCII code to an RS232C
device
1) The end code specified in the transmission format should be
added at the end of the data. Here, “C
R
” (carriage return) is
specified.
2) Data sent using the F95 (ASC) instruction should be converted
to ASCII code data.
“ ” 1 2 3 4 5 C
R
31
(1)
32
(2)
33
(3)
34
(4)
35
(5)
0D
(C
R
)
H
Conversion of ASCII code
Conversion of ASCII code
(Data to be sent)
(Coded data)
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