ASK-411 digital the PT monitoring and control switching device, the main two sets of bus PT automatically switch, remote switching function as a subsystem of the substation automation. This device can be done in the case of a group of PT quit running another group PT voltage automatic switching, avoid protection device low-voltage protection action can also be achieved by remote control or manually PT tied. Main functions: protection functions a) PT automatic switching function, PT remote switching function; b) over-voltage, low-voltage, zero sequence overvoltage alarm or trip; c) the bus PT breakage, insulation monitoring function. Device self-test function a) installation of automatic detection of RAM, ROM, A / D and the power disappears failure; b) automatically detect settings, configuration, coefficient parameters. Event log a) the contents of the log events including protective action event, the device self-test failure; b) record the protection action type of event, time of action and protection action when the operating parameters; recording device self-test failure event type and time of occurrence. Communication functions a) device to upload real-time data, including measurement data, fault, alarm signals and protection setting value configured coefficient. Distant Online modify the setting and cast-off protection function; b) to receive the higher control commands issued, including: system tuning and data read and write commands given value. Monitoring function a) device has a measurement of voltage, frequency analog the telemetry functions; b) acquisition disconnector position signals and other remote signaling function of the switch signal. Panel display features a) has a Chinese character LCD status indicator and keyboard operation, you can easily achieve measurement tracking and monitoring, on-line to modify the setpoint or cast back protection function, can be the reversion key or remote control to revert to the fault indicator.