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Verfügbare Sprachen
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3. Safety
3.8 Signal jump electronics
An external safety control system independent of the force transducer must monitor the
safe functioning of the force transducer. The functional test with a signal jump of
EN
4 mA / 2 V is executed at an interval of 24 hours. The safety control system activates the
relay A, thus changing the output signal of the force transducer in a defined manner.
If the expected change in the output signal occurs, it can be assumed that the entire
signal path from the Wheatstone bridge via the amplifier through to the output is
functioning correctly. If this does not occur, then it can be concluded that there is a error
in the signal path.
Moreover, the measuring signal should be checked by the safety control for the min.
(A) and max. (B) signal value to ensure that any cable break or short-circuit that has
occurred is detected.
The default setting of the force transducer with current output 4 ... 20 mA for overload
detection is, for example:
3.8
4
16
20 21
[mA]
Cable break (A)
Short-circuit (B)
(100 % rated load)
Overload point
Signals of the signal jump electronics
With a fixed signal jump of, for example, 4 mA, the test cycle can then be triggered, in any
operating state, by activating the test relay. The upper measuring range limit of 20 mA will
never be reached and thus the checking of the signal jump is enabled.
12
Operating instructions, models F5301, F53C1, F5308, F53C8, F53S8
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