Azbil F4Q, User Manual

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Chapter 4. CPL Communication
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Application layer
The application layer contains instruction codes, start data address, data, number
of data records, and information on the success of the instruction message
(termination code). In the application layer, the structure of the instruction message
is different from that of the response message.
There are two types of instruction message: read and write. The response message
corresponds to one of these types of instruction message. The termination code
indicates how the instruction message was processed.
The application layer of the instruction message is composed of the following 4
items:
Item Description
(1) Command "RS" (consecutive address data read command in decimal format)
"WS" (consecutive address data write command in decimal format)
"RD" (fixed length consecutive address data read command in
hexadecimal format)
"WD" (fixed length consecutive address data write command in
hexadecimal format)
(2) Data delimiter RS/WS: "," (comma)
RD/WD: None
(3) Data address RS/WS: "W" is added to a decimal number, as in "1001W.”
RD/WD: A four-digit hexadecimal number such as "03E9"
(4)-1 Read count RS: A decimal number such as "1"
RD: A four-digit hexadecimal number such as "0001"
(4)-2 Value to write WS: Value of character expression such as "123"
WD: A four-digit hexadecimal number such as "007B"