Michell Instruments SF82 Series, Руководство пользователя

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SF82 Transmitter User’s Manual
27 Michell Instruments
Modbus Register Map
All the data values relating to the SF82 are stored in 16-bit wide holding registers. Registers can
contain either measured or calculated values (dew-point, temperature, etc.), or configuration
data (output settings).
Modbus RTU Implementation
This is a partial implementation of the Modbus RTU Standard with the following codes
implemented:
Function Code Description
3 Read Holding Register
6 Write Holding Register
16 Write Multiple Holding Registers
Register Types
Data Type Description
uint16
16-bit unsigned integer, can contain options list e.g. 0 = Dew Point, 1 =
Temperature.
int16 16-bit signed integer.
int32 32-bit signed integer, stored across 2 16-bit registers.
float IEEE754 single precision floating pint, stored across 2 16-bit registers
Serial Port Settings (RS485)
9600 Baud Rate, 8 Data Bits, No Parity, 1 Stop Bit, No Flow Control
http://www.simplymodbus.ca/FAQ.htm is an excellent
resource covering the basics of the Modbus protocol. Full
descriptions of the function codes (FC03/FC06/FC16) can
be found in the sidebar.
https://www.scadacore.com/tools/programming-
calculators/online-hex-converter/ is an excellent resource
for determining register types/byte order issues in raw
received Modbus data.