Datcon DT13 Series, Руководство пользователя

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4.2. Inputs with 0,5 mA current
Inputs with 0.5 mA current are available optionally to satisfy specific customer needs.
Input parameters:
Short-circuit current: < 0.5 mA

6%
Input resistance: 18 k

.
5. Operating principle
.
The operation of the device is shown in the block diagram of Figure 1.
Figure 1. The theoretical build-up of the device
The comparator unit detects the current flowing over the 1 k

resistor connected serially with the +8.2 V voltage
generator. The threshold values in accordance with the NAMUR standard are as follows:
Direct switch position: > 2.1 mA
Reverse switch position: < 1.2 mA
Sensor line broken: < 0.15 mA
Sensor line short: > 6.0 mA
The following settings can be realized with the operating mode switch mounted inside the device (triple DIL-
switch):
S1, Direct – Reverse
S2, Detecting if the line is broken
S3, Detecting if the line is short
The function of detecting if the line is broken or short is applicable only when a NAMUR input detector is used!
In the case of operation with contact switch, the network in accordance with Figure 2 must be used for
establishing the connection to the contact switch ( S2 and S3 in ON position ).