Rockwell Automation 1734sc-IE4CH E+H Instruments via HART to PlantPAx User Manual - Manual (Page 94)

94 Rockwell Automation Publication PROCES-UM002A-EN-P - July 2014
Appendix C Promass 83 Coriolis Mass Flowmeter
The phase difference (A-B) increases with increasing mass flow. Electrodynamic
sensors register the tube oscillations at the inlet and outlet. System balance is
ensured by the antiphase oscillation of the two measuring tubes. The measuring
principle operates independently of temperature, pressure, viscosity, conductivity
and flow profile.
Measured Variables
• Mass flow (proportional to the phase difference between two sensors
mounted on the measuring tube to register a phase shift in the oscillation)
• Volume flow (calculated from mass flow and fluid density. The density is
proportional to the resonance frequency of the measuring tubes.)
• Measuring tube temperature (by temperature sensors) for calculatory
compensation of temperature effects
• Density by monitoring the tube frequency is directly proportional to
medium density
• Totalized flow (application dependent using pulse output)
Signals from Instrument to Control System
Connect a Promass 83
Flowmeter Use a 4-wire connection to the HART input module.
Supply 100V AC power to the field instrument. Connect instrument
communication to the HART terminals. The sensor was preinstalled at the
factory.
1. Remove the cover of the connection compartment (f ) from the
transmitter housing.
2. Feed the power supply cable (a) and signal cables (b) through the
appropriate cable entries
3. Connect the HART communications cable to the HART connector in
the order white (+), black (-) on pins 26, 27 of the connector.
4. For AC powered instruments, connect the AC cable to the power
connector in the order ground (as shown), black (pin 1), white (pin 2).
Signal Details
Current Signal Active/passive selectable, galvanically isolated.
• Active: 0/4...20 mA, R
L
< 700
Ω (for HART: R
L
≥ 250 Ω)
• Passive: 4...20 mA; supply voltage U
S
18...30V DC; R
i
≥ 150 Ω
Pulse/Frequency Signal Active/passive selectable, galvanically isolated.
• Active: 24 V DC, 25 mA (max. 250 mA during 20 ms), RL > 100
Ω
• Passive, open collector, 30V DC, 250 mA
• Frequency output: full scale frequency 2...10000 Hz (f
max
= 12500 Hz), on/off ratio 1:1, pulse width max. 2 s
• Pulse output: pulse value and pulse polarity selectable, pulse width configurable (0.05...2000 ms)