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Consider the following inputs and outputs associated with a DCS system. It is interesting to note that EXACTLY the same could be applicable to a SCADA system (although the SCADA system could use either a dedicated RTU or else a PLC).
Break the following signals up (either going to, or away from the RTU-type devices) and indicate which are:
i) digital inputs, ii) digital outputs, iii) analog inputs and iv) analog outputs:
18.1 ( 1 mark) START signal
18.2 ( 1 mark) | Speed control signal of a VSD (going to the VSD – Please think in terms of a SPEED UP button and a SLOW DOWN button). |
18.3( 1 mark) An I/P (current to pressure) transducer for a butterfly valve (going to the valve).
18.4( 1 mark) Solenoid Valve (operating something in the field).
18.5( 1 mark) A light.
18.6( 1 mark) An electric motor’s contactor (which will be used to start a motor in the field)
18.7( 1 mark) An RTD temperature probe.
Note – This question is mandatory. It should be answered and students are expected to get this question completely right to be assessed as competent with a score for this module.
