NIVELCO EasyTREK SCD-31 4 Series, Installation And Programming Manual, Page: 6 / 32

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scd340en21p07
The following types of applications are possible depending on the communication and what the output signal is used for:
1. 1.Using the unit as a three - or four -wire current transmitter.
Normally, we use the analogue (4…20 mA) output signal of the EasyTREK. The application parameters of the device are set through HART communication
at installation (right after installation or in a laboratory, prior to installation). In this case the short address of the device should stay the factory default: P19 =
0.
2. 2.Using both, current transmission and digital (HART) signal transfer in single transmitter systems.
Digital signal transfer is also used beside the standard utilization of the output current of the EasyTREK. In this case, there can be one or more devices in the
current loop that use analogue signals (with their total resistance being R
t
= 250 … 600

) and one HART master device.
The short address of the EasyTREK should stay the factory default: P19 = 0. This application can be achieved with using a MultiCONT unit as the HART
master which ensures the power supply of the EasyTREK too.
3. 3.Simultaneous control of several EasyTREK transmitters with the help of a MultiCONT.
In this case all of the EasyTREK s keep the connection with the MultiCONT through HART communication only.
This means that the measurement values are collected in cycles, and that the modifications of the transmitter settings are arbitrary.
The short addresses of the units are P19 = 1…15. All types of setting and programming tasks can be done through a MultiCONT.
2. TECHICAL DATA
2.1. General data
Type SCD–3

–

Transducer material
Closed cell PVC foam sensor face
PP and Aluminum transducer housing and fitting
Beam angle 
5°
Process temperature –30…+60 °C ( − 22…+140 °F)
Process pressure (absolute)
0.7…1.1 bar (10…16 psi) P
absolute
and ± 0.1 bar (±1.45 psig)
difference between ambient and tank/silo pressure
Power supply / consumption 11.4…40 V DC / 4.1 W or 11.4…28 V AC (50/60Hz) / 4,6 VA
Accuracy*

(0.2 % of the measured di 0.1% of the measurement range)
Resolution 10 mm (0.4 inch)
Output
Analog
4…20 mA, R
tmax
= 600 Ω , galvanic isolation, protection against surge transients
If no echo: continuous 3.6 mA or 22 mA (selectable with programming)
Relay Relay (SPST), 48V AC / 5 A
Digital communication HART ® standard on the current output
Damping time 3…1000 s (selectable with programming) Default value: 300 s
Electrical connection 7x0.5 mm
2
(AWG20) shielded cable  7.5 mm (Ø0.3 inch) standard length: 3 m (16.5 ft) (available to order up to 30 m [100 ft])
Electrical protection Class III
Ingress protection IP 65
* Under optimal conditions and constant transducer temperature.