User manual

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6
Fig. 5.7 Voltage signal wiring
Table 5.1 Terminal assignment
Designation
Description
24VDC -
Power supply
24VDC +
DO-
Output -
DO+
Output +
AI1
+ (three-wire RTD)
AI2
+
AI3
–
Table 5.2 Sensor cables
Sensor
type
Cable length, max.
Resistance
(each wire), max.
Requirement
RTD 100 m 30 ohm
Equal length and cross-
section for 3-wire
TC
20 m
100 ohm
Thermocouple cable
5.1.2 Output
The NPN transistor output is designed to control the low voltage relay up to 42 V DC / 200
mA
►
NOTICE
As a precaution against inadvertent current reversal on output, a parallel diode (U
VD
≥ 1.3U, I
VD
≥ 1.3I) is usually included in the output circuit.
Fig. 5.8 NPN transistor output
6 Operation
After the device is powered on the operating mode is activated. In this mode the measured
signal is scaled and displayed. The signal type must be selected in the parameter in.t “Input
signal”. The complete list of the programming parameters is shown in Table 7.2.
The input signal is digitalised, the square root calculated (if the function is enabled), the
signal scaled and displayed. The scale factor is calculated based on the parameters di.Lo
“Lower measuring limit” and di.Hi “Upper measuring limit”. The display decimal point can be
specified in the parameter di.P. For other signal processing functions see 6.2 and 6.3. For
displayed errors see Table 6.1.
6.1 Control
ON/OFF control is implemented with the NPN transistor output (see 5.1.2). The parameters
SP.Lo “Lower setpoint limit” and SP.Hi “Upper setpoint limit” specify the control limits. The
control function can be selected in the parameter Cnt:
DO-
K
_
U
U
+
VD
DO+