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4.16 Nameplate
5 Variants of Input Connections
5.1 Absolute Value Measurement
The absolute value measurement with only one measuring input is a possibility of
interconnection with the signal source (e.g. 0-1000 VDC) and the transmitter, if the
terminals T-18 and T-19 are bridged
However, it does not meet the requirements of the IEC 61508 standard according to SIL2.
A line break in the measuring circuit would be detected by the transmitter with 0 VDC, since
the connection to the Measurement input E1 is interrupted. However, the maximum voltage
value in the signal source could still be 1000 VDC and mean a massive danger or danger to
life!
5.2 Redundant Absolute Value Measurement
A line break monitoring is available for all 4 input lines, if the measurement signal has a
value > 0 V. The transmitter then detects the line break and triggers the safety function. A
series connection of the mA output with the REL3 or REL4 contact (NO) ensures that with
the triggering of the safety function, the mA value is always 0 mA.
Fig. 4
Fig. 5
Fig. 6
