OTT SE 200, Operating Instructions Manual

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7 Determine the maximum load resistance
(4 … 20 mA interface)
The load resistance connected to the SE must not exceed a specific maximum
value. This value depends on the level of the supply voltage to the SE 200. If the
load resistance is greater, the output current can no longer be evaluated. Smaller
load resistances are allowed.
䡵
Read off the maximum load resistance for your supply voltage from the
following diagram.
Example: Supply voltage 18 Volts
→
max. load resistance 450 Ohm.
The SE 200 delivers an output current corresponding to the measured value for
a load resistance of up to 450 Ohms.
䡵
Dimension the connected electrical circuit accordingly. Check the input
resistance of the connected peripheral device for this purpose.
10 15 20 25 30
U
V
100
0
200
300
400
500
600
700
800
R
Ω
900
1000
Ex.
Fig. 9: Diagram to determine the
maximum load resistance as a
function of supply voltage.
M inimum supply voltage: 9 V
M aximum supply voltage: 30 V
Resistor tolerance: 0.1 %/15 ppm!
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