Selection between PLC and DCS
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32,000 digital inputs and 2,000 analog inputs – which PLC is suitable?
30,000 digital values? PLC? Have you got it wrong!
It depends on your budget. First, decide whether to use domestic or imported products. For controlling such a large scale, a large-scale distributed DCS system should be employed; given the high proportion of digital signals, attention must be paid to the response time of the IO cards as well as the selection of the sampling voltage level.
With so many digital switches, batch control should be available; pay attention to the software’s configuration functions. I believe that the ABBAC900 DCS system is a suitable choice; its price is moderate, around 24 million or less. Other imported systems such as DELTAV, Westinghouse, Yokogawa, Siemens, Honeywell, etc., should cost more than this amount
First of all, your required points are too high; a PLC cannot meet these requirements. In terms of cost-performance, it is recommended to choose a DCS
34,000 points plus 20% as a safety margin amounts to roughly 40,000 points; in such a case, it’s clear that DCS should be the chosen solution. With so many digital inputs, as mentioned above, sequential control will likely be used extensively. Therefore, when selecting a system, it’s important to pay attention to the ease of use and readability of the software related to sequential control, as well as whether maintenance will be straightforward later on, since this can be quite troublesome during the start-up and shutdown of the equipment. Although PLCs focus on logical control, such a large volume of data requires strong data processing capabilities; DCS is more reliable.
Honeywell is the recommended choice for you