Burkert Type SE56 - Manual (Page 13)

TECHNICAL MANUAL Rev. Pagine 13/52
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03 PROFIBUS DP MODULE- DATA LINK
DESCRIPTION
Document Data Date Date
File name ProfibusDP_emanual_Burkert_04.doc 19/03/08 19/03/08 19/03/08
13
The connectors must allow these connections.
Parameter DP, Cable type A
Surge impedance in Ω 135...165 for a frequency of 3...20 MHz
Effective capacitance (pF/m) ≤ 30
Loop resistance ( Ω/km) ≤ 110
Core design (solid) AWG 22/1
Core design (flexible) > 0,32 mm²
The table shows the cable parameters for PROFIBUS copper signal cables with RS-485 transmission
standard.
2. CYCLIC DATA EXCHANGE
With the Cyclic Service of data exchange the slave return Dynamic Data that include measurement
values which are continuously changing e.g. Flow rate, totalizers, etc..
The module support five type of configurations with is possible sets the better combination of type of
information of the Flow meter.
The type of Configuration is set in the file GSD.
Below there are the description of the possible types of configuration with the realtive structure of data:
2.1. FIRST CONFIGURATION: 8 BYTE INPUT
Below there is a description of the contents of each byte:
bytes 0-3:
(32 bit single precision IEEE floating point, MSB first) Flow rate in % or Flow rate in t.u. or
(32 bit long integer, MSB first) totalizer for TOTAL or PARTIAL volume + or - or batch quantity
(see section 2.2 Data Type)
bytes 4-5: (16 bit unsigned integer, MSB first) process flags:
bit 0 =1 if the excitation is too fast for the sensor connected
bit 1 =1 if the maximum alarm is active
bit 2 =1 if the minimum alarm is active
bit 3 =1 if the Flow rate exceeds the scale range value (overflow)
bit 4 =1 if one or more output impulses are saturated (too many impulses to emit)
bit 5 =1 if the measurement signal is highly disturbed or if the sensor is disconnected
bit 6 =1 if the measurement tube is empty
bit 7 =1 if the circuit powering the coils is not working or the sensor is disconnected
bit 8 =1 if the second measurement scale is active
bit 9 =1 if the Flow rate is lower than the cut-off threshold
bit10=1 if the Flow rate is negative
bit11=1 if a new measurement value calculated for the display is available
bit12=1 if the counter block signal is active
bit13=1 if dosing is in progress
bit14=1 if a calibration cycle is in progress
bit15=1 if a Flow rate simulation is in progress
byte 6: (8 bits integer) measurement dynamic variation as a %
byte 7: (8 bits integer) Data Type ( see section 2.2 Data Type )
NOTE: The values in the “32 bits single precision IEEE floating point” format are floating point numbers
which can be represented during writing by any decimal digits. To keep the same numerical format visible