Regarding control system cards
Thread Content
For combustible gas concentration alarms, there are two DI points: a high alarm and a very high alarm (a concentration of 20% triggers the high alarm, while 40% triggers the very high alarm). When this is integrated into the PLC system, is it necessary to use 1 DI card or 2 DI cards?
DI card? Is it an expansion module? One is enough; there should be at least over 2 DI points.
Does your combustible gas detector have two alarm outputs? If it has two alarm outputs, then two DI points are required; if it has a 4–20mA output, only one AI point is needed. The alarms are implemented through point configuration. The alarm threshold for combustible gas concentration is generally above 60 LEL; 20 LEL is too low
Flammable gas concentration alarms generally provide digital output, with two separate switch circuits that are fed into the corresponding DI modules of the PLC; 2 DI channels are required. DI modules generally have 8, 16, or 32 channels, so one module is sufficient.