Analog I/O slice for process monitoring
The ABB 1SAP450100R0001 AX521-XC module squeezes four analog inputs and four analog outputs into a compact IP20 housing. On the input side it handles voltage, current, RTD, and even digital input signals—useful for mixed-signal field panels without needing a separate DI slice. The 13-bit resolution on the analog inputs is adequate for standard process monitoring: RTD temperature and 4-20 mA loops. The outputs are voltage or current, so you can drive valve positioners or chart recorders directly.