Magnetic pick ups, shaft pick ups, potential transformers, and breaker relays are
wired to two I/O terminal blocks on TTUR. Each block is held down with two
screws and has 24 terminals accepting up to #12 AWG wires. A shield termination
strip attached to chassis ground is located immediately to the left of each terminal
block. Jumpers JP1 and JP2 select either SMX or TMR for relay drivers K25 and
K25P. TB3 is for optional TTL connections to active speed pickups; these require an
external power supply.