Product Overview

The ABB 086351-004​ (also referenced as 086351-004/000 in some parts lists) is a Printed Wiring Assembly (PWA / PCB) functioning as a Serial Pushbutton and Indicator Interface Board, designed for internal mounting within ABB HKQCS-series (Human-Knowledge QCS) operator consoles, Advant OCS free-standing operator desks, and certain System 800xA process operator console configurations that utilize hardwired mechanical pushbuttons, key switches, and lamp/LED annunciator panels. The ABB 086351-004​ serves as the electronic “bridge” between the physical operator interface elements—Start/Stop pushbuttons, Acknowledgment buttons, Mode Select key switches, and illuminated indicator lamps—and the console’s main processing/communication backplane, which in turn connects to the DCS node (AC450, AC800M/F, or 800xA Connectivity Server depending on system vintage).The ABB 086351-004​ performs continuous matrix scanning of connected pushbutton and key-switch contacts, debounces the inputs in hardware/firmware, and encodes button press/release events into serial data packets transmitted over the console’s internal proprietary serial bus to the host controller card in the operator desk. Conversely, it receives serial commands from the host that dictate which indicator lamps (LEDs) should be lit—reflecting process alarm states, controller mode (Auto/Man/Cas), or acknowledgement pending—and drives the lamp matrix accordingly with current-limited outputs. The board is powered from the console’s 24 V DC distribution (typical operating range 10–30 V DC) and mounts via standoffs or edge connectors onto the console’s internal card cage / backplane. Because the ABB 086351-004​ is an internal spare assembly rather than a field-mount I/O module, it is not intended for standalone use—its value lies in being the authentic ABB-replacement circuit board that restores full functionality to an HKQCS or Advant operator console whose original button-interface card has failed due to age-related component drift, ESD damage, or backplane connector wear. For plants running ABB DCS with hardwired console buttons (as opposed to pure touchscreen HMI), the ABB 086351-004​ is a strategically stocked MRO item to prevent extended downtime when a console’s pushbutton responsiveness or lamp feedback is lost.

Technical Specifications