The 9470/22 series digital input module for Zone 1 has 16 channels for Exi operating zero-potential contacts or NAMUR proximity sensors.
Channels 14 and 15 can also be configured for frequency measurements or as a pulse counter for frequencies of up to 20 kHz. All inputs are short-circuit proof, galvanically separated from the system and individually monitored to check for wire breakage/short-circuiting.