Fp_32Bits_3Dp; Uint32; Uint16 - Siemens 7SR242 Duobias Technical Manual

On reception these two registers should be interpreted in the correct order as IEEE754 floating point
representation.

4.2.2 FP_32BITS_3DP

The FP_32BITS_3DP is a 32 bit integer fixed point value, containing 3 decimal places of information. It is used
to send a real value to 3 decimal places as an integer. For example, if the value in a device is 123.456 it will
be sent as 123456. As it is an integer, negative numbers are sent as 2's complement.
FP_32BITS_3DP & MODBUS
In this MODBUS implementation the 32 bit value is stored in 2 16 registers in Big-Endian format. As
an example, if we take the hex representation of 123456, we have 1E240h. Assume this is stored in
the registers 30001 and 30002, it would look as follows:
On reception these two registers should be interpreted in the correct order as a 32 bit integer.

4.2.3 UINT32

The UINT32 is a signed 32 bit integer. As it is an integer, negative numbers are sent as 2's complement.
UINT32 & MODBUS
In this MODBUS implementation the 32 bit value is stored in 2 16 bit registers in Big-Endian format. As
an example, if we take the hex representation of -123456, in 2's complement, we have FFFE1DC0h.
Assume this is stored in the registers 30001 and 30002, it would look as follows:
On reception these two registers should be interpreted in the correct order as a 32 bit integer.

4.2.4 UINT16

The UINT16 is a signed 16 bit integer. As it is an integer, negative numbers are sent as 2's complement.
UINT16 & MODBUS
In this MODBUS implementation the 16 bit value is stored in a 16 bit register in Big-Endian format. As
an example, if we take the hex representation of 5678 we have 162Eh. Assume this is stored in the
register 30001, it would look as follows:
On reception this register should be interpreted as a 16 bit integer.
© 2015 Siemens Protection Devices Limited
Chapter 4 - 7SR242 Duobias · Data Communications Definitions
Address Value
30002 2400
Address Value
30001
30002 E240
Address Value
30001 FFFE
30002 1DC0
Address Value
30001 162E
1
Chapter 4 - Page 35 of 92