VEGA VEGACOM 557 Profibus DP - Manual (Page 22)

22 VEGACOM 557 Profibus DP
4 Measurement loop in VEGAMET/VEGALOG
Generally a measurement loop in VEGAMET/VEGALOG processing systems is structured as
follows:
A sensor delivers the sensor value to the input of the processing system. This sensor value is
then further processing in the processed system (.e.g. empty/full adjustment, linearisation ...).
The processed values are outputted (e.g. via current outputs, relay outputs ...). The PC/DCS
output is available as gateway for VEGACOM 557, i.e. the processing system transmits the
PC/DCS output value via the DISBUS or LOGBUS to VEGACOM 557. This values are accessi-
ble to the PC/DCS system via the field bus.
Fundamental configuration of a measurement loop
VEGALOG / VEGAMET
DISBUS LOGBUS
DISBUS
or
LOGBUS
PC/DCS system VEGACOM 557
VBUS, 4...20mA
Fieldbus
Sensors
Sensor value
VEGALOG/
VEGAMET input
Empty/
full
adjustment
Linear-
isation
Scaling
Parameter
selection
Unit: 0,00%
(Resolution= 0...10000)
Unit: 0,00%
Unit: 0,0%
VEGALOG/VEGAMET
PC/DCS output
LOGBUS/
DISBUS
Fieldbus PC/DCS
system
Unit: 0,0%
(Resolution= 0...1000)
PC/DCS value
Parameter:
Percent
Volume
percent Scaled
selected
parameter+
unit
mA
bar
m
Measurement loop in VEGAMET/VEGALOG