DO3401

• SIL 3 Rated: Complies with high industrial safety ratings for emergency shutdown
• Allows online module replacement without interrupting safety processes
• Integrates continuous diagnostics with channel self-limiting short-circuit protection

DO3401 is certified for stringent SIL 3 safety applications. Each output channel integrates self-limiting current and overload protection, with a maximum reverse voltage tolerance of -0.6 VDC and a channel limit near 5A. This design ensures that neither the module nor the upper control system is damaged during field actuator short-circuits or electrical ground faults.

The Digital Output (DO) Module contains the circuitry for three identical, isolated channels. Each channel includes a proprietary ASIC which receives its output table from the I⁄O communication processor on its corresponding main processor. DO Modules use special quad output circuitry to vote on the individual output signals just before they are applied to the load.

This voter circuitry is based on parallel series paths which pass power if the drivers for channels A and B, or channels B and C, or channels A and C command them to close; in other words, two out of three drivers are voted on. The quad output circuitry provides multiple redundancy for all critical signal paths, guaranteeing safety and maximum availability.