The BAE SYSTEMS' Mobile Trusted Filter is a filter for asynchronous serial data that can be used in a number of applications, primarily to provide RED/BLACK separation in systems where BLACK equipment is remotely controlled from a RED area via a serial remote control port.
The Trusted Filter provides RED/BLACK separation in systems where control data, which cannot be protected by other means, must cross a RED/BLACK boundary. This is achieved by the filtering of RED data to produce ORANGE data. The control data is in the form of various length character strings. The control data is in plaintext.
Data passing from RED to BLACK is filtered in accordance with a table of allowable commands encoded in an EPROM, which cannot be modified in the field. The filter ensures that only control data of a pre-defined nature is passed. Only valid control data is passed to the BLACK area. Invalid control data is discarded.
The filter provides a single data channel, with a data diode provided for the BLACK to RED data path.
The operator interface consists of one diagnostic LED, with connectors for status and reset on the front panel.
The Mobile Trusted Filter case conforms to the VME standard for card assemblies. The filter can be mounted in a VME standard chassis, using 1 slot and requiring 5V DC via the front panel.