Uart Interface; Modbus Protocol Over Uart Interface - E+E Elektronik EE895 User Manual

Example for reading the air pressure value (7-bit address shifted):
Request [Hex]: S BC 06 P
Slave address
Start
7-bit shifted
S
Response [Hex]: S BD 26 70 P
Slave address
Start
7-bit shifted
S
*) Reserved for future use
Conversion:
Measurand
p
Tab. 9 Interpretation of data from the response
4.2

UART Interface

4.2.1.

Modbus Protocol Over UART Interface

Modbus slave address: 0x5F
The interface settings are: Baud rate 9600, 8 Data, No parity, 1 Stop bit (9600 8 N 1)
The slave address and the interface settings are fixed, they cannot be changed by the user.
The EE895 module shall be addressed according to the specification "Modbus over serial line V1.02", see
https://modbus.org/docs/Modbus_over_serial_line_V1_02.pdf.
Modbus frame description (screenshot taken from the "Modbus over Serial Line Specification and Implementation
Guide V1.02" mentioned above):
Register
Stop
pointer
BC 06
p
low byte
high byte
BD 26
Response [Hex]
0x2670
EE895
P
p
Stop
70 P
Response [Dec]
9840
Miniature Sensor Module for CO
User Manual EE895
Value
984.0 mbar
, Temperature and Barometric Pressure | 16
2