Rishabh Instruments RISH Master 3430i, Operating Manual

Page: 33 / 62

03
Illegal Data
Value
Attempt to set a floating point variable to an invalid value
01
Illegal function
This function code is not supported by the instrument.
02
Illegal Data
Address
Attempt to access an invalid address or an attempt to read
or write part of a floating point value
Two consecutive 16 bit registers represent one parameter. Refer table 4 for the addresses
of 3X registers (Parameters measured by the instruments).
Each parameter is held in the 3X registers. Modbus Code 04 is used to access all parameters.
Example :
To read parameter ,
Volts 3 : Start address = 04 (Hex) Number of registers = 02
Note : Number of registers = Number of parameters x 2
Each Query for reading the data must be restricted to 20 parameters or less. Exceeding
the 20 parameter limit will cause a ModBus exception code to be returned.
Query :
Accessing 3 X register for reading measured values:
Device
Address Function
Code Start Address
High Start Address
Low Number of
Registers Hi Number of
Registers Lo
CRC
Low CRC
High
01 (Hex) 04 (Hex) 00 (Hex)
04(Hex) 00 (Hex)
02(Hex) 30 (Hex) 0A (Hex)
Start Address High : Most signicant 8 bits of starting address of the parameter requested.
Start Address low :Least signicant 8 bits of starting address of the parameter requested.
31