JUMO diraTRON Series Interface Description

3 Modbus protocol description
20
3.7 Transmission formats
3.7.1 Integer values
Integer values are transmitted via Modbus in the following sequence:
First the high byte, then the low byte.
Example
In this example, the integer value at address 0x5208 is to be extracted. The value here is to be "4" (word
value 0x0004).
3.7.2 Float values
For floating-point values, Modbus functions with the IEEE 754 standard format (32-bit), but with the dif-
ference that bytes 1 and 2 are interchanged with bytes 3 and 4.
Example
In this example, the measured value of the analog input (from word address 0x7000) is to be extracted.
The value here should be 25.0 (0x41C80000 in IEEE 754 format).
Data request:
01 03 52 08 00 01 15 70
Slave Function Address of
first word
Number of words CRC
Response:
01 03 02 00 04 B9 87
Slave Function Bytes
read
Integer value CRC
Single floating-point format (32-bit) according to standard IEEE 754
SEEEEEEE EMMMMMMM MMMMMMMM MMMMMMMM
Byte 1 Byte 2 Byte 3 Byte 4
S - Prefix sign bit
E - Exponent (two's complement)
M - 23-bit normalized mantissa
Modbus floating-point format
Modbus address x Modbus address x+1
MMMMMMMM MMMMMMMM SEEEEEEE EMMMMMMM
Byte 3 Byte 4 Byte 1 Byte 2
Data request:
01 03 70 00 00 02 DE CB
Slave Function Address of
1st word
Number of words CRC
Response:
01 03 04 00 00 41 C8 CB F5
Slave Function Bytes
read
Measured value as
floating-point value
CRC

JUMO diraTRON Series Specifications

General

Brand	JUMO
Model	diraTRON Series
Category	Controller
Language	English