MRC-U MICROPROCESSOR BASED TRACK CIRCUITS
The tone-frequency microprocessor track circuits MRC-U are designated to monitor occupancy/vacancy of track sections at stations and spans, to monitor integrity of track circuits, to transmit code signals of ALS from wayside devices to a locomotive.
A track circuit power supply module (MPRC) is a combined device containing the following:
In the “generator” mode MPRC carries out design of tone-frequency signals and ALS code signals, generating a sum signal of power supply and ALS at the output. In the “receiver” mode, the module carries out simultaneous measurement of levels of two frequency signals and their comparison with a specified setpoint.
A track circuit control module (MKRC) is designated to monitor uncoded branches of track circuits. It contains three independent two-channel RC monitoring (voltage measurement) nodes.
In MPRC and MKRC the same solutions are used as in the object controllers of MPC-U (two diverse channels, operation according to the “2oo2d” scheme).
Technical characteristics of MRC-U
Length of a track circuit
From 25 m to 1500 m (depends on track line insulation resistance and track circuit configuration)
Additional shunting zone
From 0 to 40 m
Structure of MRC-U