8
User Manual EE074 Temperature Probe with Modbus RTU
5.3 Modbus RTU Example
Example of MODBUS RTU command for reading the temperature (FLOAT value) T = 26,953624 °C
from the register 0x3EA
Device EE074; slave ID 233 [0xE9]
Decoding of floating point values:
Floating point values are stored according IEEE754 standard. The byte pairs 1, 2 and 3, 4 are inverted
as follows:
Example:
Please note:
For obtaining the correct value, both registers have to be read within the same reading
cycle. The measured value can change between two Modbus requests, therefore, exponent and
mantissa may get inconsistent.
For more details, please see the Modbus Application Note available at
and chapter 6.3 of the Modbus reference document
http://www.modbus.org/docs/Modbus_Applicati-
.
6 Maintenance and Service
EE074 does not require any special maintenance, nevertheless for high accurate measurements
especially over wide T ranges it is recommended to calibrate the probe every 12 months. If needed, the
enclosure may be cleaned and the device may be re-adjusted as described below.
6.1 Cleaning
Use a damp soft cloth to remove deposits of dust or dirt from the exterior of the probe. Do not use any
solvents or abrasive cleaning agents.
6.2 Repairs
Repairs may be carried out by the manufacturer only. The attempt of unauthorized repair excludes any
warranty claims.
Modbus ID
address
Function
code
Starting
address Hi
Starting
address Lo
No. of
register Hi
No. of
register Lo
CRC
Request [Hex]:
E9
03
03
EA
00
02
F2
93
Modbus ID
address
Function
code
Byte count Register 1
value Hi
Register 1
value Lo
Register 2
value Hi
Register 2
value Lo
CRC
Response [Hex]:
E9
03
04
A1
06
41
D7
21
CE
MMMMMMMM
MMMMMMMM
SEEEEEEE
EMMMMMMM
Byte 3
Byte 4
Byte 1
Byte 2
Response [Hex]
Value in decimal
Byte 1 (Register 2 - Hi)
Byte 2 (Register 2 – Lo)
Byte 3 (Register 1 - Hi)
Byte 4 (Register 1 - Lo)
41
D7
A1
06
26.953624
