YOKOGAWA UT150L, Руководство пользователя

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IM 05C01E22-10E
4-2
4.1.1 Configuration of Message
Messages sent from a higher-level device to UT150L, consists of the following elements.
Element
Number of bytes in ASCII mode
Number of bytes in RTU mode
Start of
Message
Mark
None
1
Address
Number
(ADR)
1
2
Function
Code
1
2
Data
2n
4n
Error
Check
2
2 2
(1) (2) (3) (4) (5) (6)
End of
Message
Mark
None
(1) Start of Message Mark
This mark indicates the start of a message. Note that only ASCII mode requires the colon.
(2) Address Number (1 to 99)
Address numbers are used by host devices to identify the UT150L at the communication destination.
(These numbers are identification numbers specific to individual UT150L.)
(3) Function Code (See subsection 3.2.1, List of Function Codes)
The function code specifies a command (function code) from the higher-level device.
(4) Data
This element specifies D register numbers, the number of D registers, parameter values, and so on in
accordance with the function code.
(5) Error Check
In RTU mode
Carried out by the cyclic redundancy check (CRC-16) system.
In ASCII mode Carried out by the longitudinal redundancy check (LRC) system.
(6) End of Message Mark
This mark indicates the end of a message.
Note that only ASCII mode requires CR + LF
●
Message format for communication
Example: When setting the target setpoint “50.0” to a UT150L, the higher-level device sends message
data (01F4) into a value of “500” converted into hexadecimals not including the decimal point (thus,
this is true for sending both 5.00 or 500).
Message data in the higher-level device: hexadecimal value of 500 (01F4)
Message data: 01F4
*
The position of the decimal point for “500” is determined by the DP (position of decimal point) parameter of the UT150L .
Response data from UT150L: 01F4
UT150L side
Target setpoint: 50.0