Xylem Expert 7060_7070_Modbus - Manual (Page 11)

Communication protocol Serie30
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5 Description of Keller bus functions
This section describes the functions of the bus protocol for Series 30 transmitters (device Class.Group 5.1 and 5.20) using the
Keller bus functions (not MODBUS).
Note that all numbers are shown as decimal (not as hex, contradictory to what was described in the MODBUS-chapters)!
Overview:
F30: Read out calibration (scaling) and information floating-point values
F31: Write calibration floating-point values
F32: Read out configurations
F33: Write configurations
F48: Initialise devices, whereby the device ID is returned
F66: Write bus address
F69: Read out serial number
F73: Read out current pressure and temperature values in floating-point format
F74: Read out current pressure and temperature values in integer format
F95: Zeroing functions
5.1 Example: read pressure value with exception handling
A simple example for reading out
a pressure value.
Because only one transmitter is
connected, the „transparent“
address 250 is used.
To read out pressure functions 73
and 48 are necessary. When the
slave replies with error no. 32
(device just recently started up,
power on), then this has to be
confirmed with function 48. This is
helpful to detect current supply
interruptions (on the power supply
circuit).
Enhancement:
During start-up the device group
can be checked via function F48
to ensure that this version is
supported.
Further information is available:
•
F30: pressure and
temperature range
• F69 serial number
Exception:
32
Request P1, funct. 73:
250 73 1 161 167
Timeout
Initialize, funct. 48:
250 48 4 67
Exception
2 or 3
Check Staus Byte:
P1, TOB1, /Std:
STAT & 0b10010010 != 0?
Transmission error
occured -> Log-File
Invalid Channel or
message -> Check
your request
Timeout
Exception:
2
Transmission error
occured -> Log-File
Incorrect length ->
Check your request
See chapter:
Error handling and
recognition
Valid Value
received
Invalid Value
received
F48: o.k.
Initialize: F48
MJK
MJK -