2 terminal blocks (72 points each), 3 × 10-pin connectors (JJR/JJT/JSS)

Signal types: magnetic pickup (overspeed), flame detector, generator V/I, synchro, protection contacts

Isolation: 250 VAC/DC channel-to-backplane

Operating temp: -40 °C to +70 °C

Features:​ 16-bit signal scaling on analog paths, built-in self-diagnostic LED, hot-replace capable, SIL-rated trip path support.

Materials & Structure:​ FR-4 multilayer PCB, tinned copper traces, metal standoff mounts, removable terminal blocks, labeled connector headers.

Working Principle:​ External analog/digital signals terminated at blocks, conditioned (filtering, scaling, isolation), then driven over 10-pin ribbon to P-core; trip signals latched and echoed to protection relays.

Installation:​ Mount in Mark V I/O cabinet panel; map every wire to identical old-board position—mismap causes turbine trip or downtime; use GE cable markers.

Precautions:​ Record wiring photo before swap; never mix JJR/JJT/JSS cables; verify isolation resistance after install; avoid static discharge on connectors.