Ahlborn ALMEMO 2690-8A, Руководство по эксплуатации

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8. Connection of the Transducers
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equipped with optocouplers. At electrically not isolated cables of the analog out-
put, the registration device or the sensors have to be potential free.
Electrically isolated A/D converter (option GT)
With option OA2690-GT the analog inputs downstream from the A/D converter
are also electrically isolated from the device itself and from the power supply by
means of optocouplers. In environments subject to particularly heavy disturb-
ance this will usually improve measuring quality; it will also be possible to supply
the device on a non electrically isolated basis - e.g. via a USB data supply cable
(ZA1919-DKU5) or a simple ALMEMO supply connector (ZA1000-FSV). It will
also be possible, via a non electrically isolated analog output cable, to perform
measuring operations at points with potentials up to 50 V.
However, some components are not electrically isolated, namely all sensors
connected to the common internal power supply ±U. For these sensors electrical
isolation has to be disabled; in some cases this will even require a switch S (see
above) or wire jumper; some inputs would otherwise be left without reference
potential. (see 11.4.8 Configuration with element flag 5 '
ISO OFF'
is usually set
automatically the first time the device is connected.) With certain connectors
(especially divider connectors without power supply) element flag 5 should be
checked and if necessary corrected.