Endress+Hauser EngyVolt RV15, Руководство по эксплуатации

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EngyVolt RV15 Appendix
47
Response
The example illustrates the normal response to a request for a single floating point parameter i.e.
two 16-bit Modbus Protocol Registers.
First Byte Last Byte
"Slave" Function
code Byte count First
register
(Hi)
First
register
(Lo) Second
register
(Hi) Second
register
(Lo) Error check
(Lo) Error check
(Hi)
"Slave" address:
8-bit value representing the address of slave that is responding.
Function code:
8-bit value which, when a copy of the function code in the query, indicates that the slave recognized
the query and has responded. (See also Exception Response (
®
ä
47)).
Byte count:
8-bit value indicating the number of data bytes contained within this response
First register (Hi)
2)
:
The top (most significant) eight bits of a 16-bit number representing the first register requested in
the query.
First register (Lo)
2)
:
The bottom (least significant) eight bits of a 16-bit number representing the first register requested
in the query.
Second register (Hi)
2)
:
The top (most significant) eight bits of a 16-bit number representing the second register requested
in the query.
Second register (Lo)
2)
:
The bottom (least significant) eight bits of a 16-bit number representing the second register requested
in the query.
Error check (Lo):
The bottom (least significant) eight bits of a 16-bit number representing the error check value.
Error check (Hi)
2)
:
The top (most significant) eight bits of a 16-bit number representing the error check value.
Exception response
If an error is detected in the content of the query (excluding parity errors and error check mismatch),
then an error response (called an exception response), will be sent to the master. The exception
2) Diese vier Byte erzeugen zusammen den Wert des abgefragten Gleitkommaparameters.