Emerson 2202 Advanced User's Manual page 21

Parameter
Introduction
x.00 description format
The 2bit type field selects the data type according to the table below:
Type field Selected data
bits 15-14 type
00 INT16
01 INT32
10 Float32
11 Reserved
If a 32bit data type is selected then the slave uses two consecutive 16bit MODBUS registers (in 'big endian'). The master must also set the correct
'number of 16bit registers'.
Example, read Pr 20.21 through Pr 20.24 as 32bit parameters using FC03 from node 8:
Table 6-9 Master request
Byte Value
0 0x08 Slave destination node address
1 0x03 FC03 multiple read
2 0x47
Start register address Pr 20.21
(0x4000 + 2021 - 1) = 18404 = 0x47E4
3 0xE4
4 0x00 Number of 16bit registers to read
Pr 20.21 through Pr 20.24 is 4x32bit registers =
5 0x08
8x16bit registers
6 CRC LSB
CRC
7
MSB
Table 6-10 Slave response
Byte Value
0 0x08 Slave destination node address
1 0x03 FC03 multiple read
Length of data (bytes) = 4x32bit registers =
2 0x10
16bytes
3-6 Pr 20.21 data
7-10 Pr 20.22 data
11-14 Pr 20.23 data
15-18 Pr 20.24 data
19 CRC LSB
20 CRC MSB
Reads when actual parameter type is different from selected
The slave will send the least significant word of a 32 bit parameter if that parameter is read as part of a 16 bit access.
The slave will sign extent the least significant word if a 16 bit parameter is accessed as a 32 bit parameter. The number of 16 bit registers must be
even during a 32 bit access.
Example, If Pr 20.21 is a 32 bit parameter with a value of 0x12345678, Pr 20.22 is a 16 bit parameter with a value of 0xABCD, and Pr 20.23 is a 16 bit
parameter with a value of 0x0123.
Commander SK Advanced User Guide
Issue Number: 9
Parameter Keypad and
display communications
Comments
backward compatible
IEEE754 standard
Not supported on all slaves
Description
Description
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Serial CT Modbus PLC Ladder
RTU programming
Parameter Advanced parameter
CTSoft
x.00 descriptions
21