18
User Manual EE741 Inline Flow Sensor for Compressed Air and Gases
The recommended baud rate for several devices in the Modbus RTU network is 9600.
Device address, baud rate, parity and stop bits can be set via:
1. EE-PCS, Product Configuration Software and USB configuration interface (see chapter 5.3).
The EE-PCS can be downloaded free of charge from www.epluse.com/configurator
2. Modbus protocol in the register 60001 (0x00) and 60002 (0x01).
See Application Note Modbus AN0103 (available on www.epluse.com/EE741)
The serial number as ASCII-code is located at read register address 30001-30008 (16 bits per
address).
The firmware version is located at register address 30009 (bit 15...8 = major release; bit 7...0 =
minor release). The sensor name is located at register address 30010.
Please note:
When reading the serial number or the sensor name, it is always necessary to read
all 8 registers, even if the desired information requires less.
Please note:
For obtaining the correct floating point values, 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.
Communication settings (INTEGER 16 bit)
Parameter
Register number
1)
[DEC]
Register address
2)
[HEX]
Write register: function code 0x06
Slave ID (Modbus address)
1
0x00
Modbus protocol settings
3)
2
0x01
1) Register number starts from 1.
2) Register address starts from 0.
3) For Modbus protocol settings see Application Note Modbus AN0103 (available at
).
INFO (read register)
Parameter
Register number
1)
[DEC]
Register address
2)
[HEX]
Read register: function code 0x03 / 0x04
Serial number (as ASCII)
1
0x00
Firmware version
9
0x08
Sensor Name
10
0x09
1) Register number starts from 1.
2) Register address starts from 0.
Bus termination resistor:
Bus termination is required for the last flow sensor in a Modbus RTU network. The 120 Ohm
termination resistor is located behind the blind of the USB port and can be switched on and off
Fig. 14
Bus termination resistor
