Ansaldo N4519106901 Protection Relay Module is a Microlok II interlocking component sold as an Ansaldo Cab Amplifier for railway signaling systems. The N451910-6901 variant is noted to generate a 40 Hz or 50 Hz carrier for special applications. In MicroLok II, vital-circuit protection uses a VCOR (vital cut-off relay) that the CPS circuit energizes from the CPU signal to control power to all vital functions. The module is part of the Microlok II interlocking family, whose design standards cover signaling interlocks and protection logic used in railway applications.
