There are DC 5V, DC 12V, DC 24V, DC 48V, AC 110V and AC 220V input modules. Each module has different points from 4 points to 16 points.
ST-1114
4 digital inputs
5 VDC
Positive logic (PNP)
ST-1214
4 digital inputs
12/24 VDC
Positive logic (PNP)
ST-1218
8 digital inputs
12/24 VDC
Positive logic (PNP)
ST-121F
16 digital inputs
12/24 VDC
Positive logic (PNP)
ST-1314
4 digital inputs
48 VDC
Positive logic (PNP)
ST-1804
4 digital inputs
120 VAC
Positive logic (PNP)
ST-1904
4 digital inputs
230 VAC