pH 298, LF 298, Oxi 298, Cl 298
Communication with Modbus RTU
59
ba77196e03
07/2018
T1 for different
baud rates
6.4
Coded data for fieldbus communication
6.4.1 Data formats of the sensor data block
Measured values
(Float 32)
The data for temperature, main and secondary measured value are transmitted
in IEE-754 Standard 32-Bit Floating Point format.
* MSB = Most significant bit, LSB = Least significant bit
Other data (INT8)
All other data consist of only one byte each (Int8).
figure 6-2 Data traffic and timeout periods (T1 ... T3)
1 Data query master
2 Response slave
3
T1
: Final recognition of query protocol (attention - depending on the
baud rate, always 3 characters long)
4
T2
: Working time of slave (max. 100mS), during this time no other
data query may be in the bus.
5
T3
: Switching time from send to receive max. 10 mS
3
3
5
4
T
1
T
1
T
3
T
2
2
1
1
Baud rate
T1 in mS final recognition
9600
4,2
19200
2,18
38400
1,15
Address
Bit representation
Offset 0h bits 31-24
S = sign (bit 31)
E = exponent
(bits 30-23)
M = mantissa (bits 22-0)
Offset 1h bits 23-16
Offset 2h bits 15-8
Offset 3h bits 7-0
MSB*
LSB*
S E E E E E E E
E M M M M M M M
M M M M M M M M
M M M M M M M M
Summary of Contents for CL 298
Page 6: ...Contents pH 298 LF 298 Oxi 298 Cl 298 6 ba77196e03 07 2018...
Page 75: ......
