KROHNE Summit 8800 Vol 2 - Manual (Page 85)

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08/2013 - MA SUMMIT 8800 Vol2 R02 en
SUMMIT 8800 STREAM CONFIGURATION 06
DP Sensor Select how many transmitters, configured in the hardware, will be used in the
selection process for this range. The actual transmitters must be defined in the
hardware section. Choosing zero means that there are no direct transmitters, but
the value may come from a serial link (e.g. SCADA) or that a keypad value will be
used.
DP Keypad A user defined value that the SUMMIT 8800 will use in case the DP transmitter
fails or is not available. The keypad value may later be changed via the SUMMIT
display if security allows such.
DP max & min Maximum and minimum alarm limits: generates an accounted alarm when
exceeded.
DP high & low High and low warning ranges: results in a warning when exceeded. These values
should be within the DP max & min values.
6 .2 .3 .4 .1 DP select
This section defines the selection process to arrive to an “in use” value for the range. There are
6 options in order of priority with each 6 choices. The SUMMIT will start to check the first option.
If the value is valid (not in alarm) then this option will be choosen. If not, then the second op-
tion will be checked etc. The last option is always the keypad value as defined earlier, even if all
other choices are none.
The 6 choices provided for the DP selection are:
None No functionality or transmitter selected, the option will be skipped.
Keypad The user defined value for this range will be choosen.
Sensor 1-3 The transmitter value, as configure in hardware, will be used.
Average Average value of all transmitters (selected in DP sensor) will be used.
Serial Value as sent by Modbus e.g. from a PLC, or smart transmitter will be used.
Last good value The last good value known before loss of signal will be used.
6 .2 .3 .4 .2 Calibration constants
The DP calibration range and offset which are the scaling factors for the transmitter, determined
during the calibration of the transmitter. As this is a multiplier to the normal transmitter range
and offset, this is not a mandatory setting, but a software calibration. This is used to correct the
transmitter value without actually calibrating the transmitter itself. The advantage is that the
changes will appear in the audit log.
This setting is also ideal for simulation purposes. With it, the transmitter can be set to any value
without an actual transmitter connected.
Figure 76 Define the differential pressure transmitter calibration constants