The 6ES7326-1BK02-0AB0 is a fail-safe digital I/O module with 24 inputs and 4 isolated outputs. It achieves SIL 3, Category 4, with fail-safe operation and diagnostic alarms. Rated for 24 V DC and drawing up to 450 mA from load voltage L+ (plus 100 mA from the backplane bus), this module is designed for 2-wire sensors with a permissible quiescent current of 2 mA. It handles sensor cable runs up to 200 m shielded or 100 m unshielded, with switching times of 3.4 ms both directions.
What the Ratings Mean for Your Panel
With SIL 3 and Category 4, this module meets the highest safety integrity level for single-fault-tolerant machinery safety functions. It generates a diagnostic alarm for group errors (SF red LED) and readable diagnostics, which simplifies troubleshooting in a safety circuit. The isolation between channels (in groups of 12) and between channels and backplane bus allows mixing safe and unsafe signals without grounding concerns, as long as isolation is tested at 500 V DC/350 V AC. Outputs limited to 24 simultaneously on at rated conditions; derate at higher temperature. Draws 10 W typical. Dimensions: 120 x 80 mm.