GMX-CS is a Generic Product, not a finished computer.
A SIL 4 Generic Product based on the GeminiX-Platform, with a dual diverse electronic structure and boards for safe digital inputs and outputs. You build a Generic Application on it. We are explicit about where the boundary runs.
Image: the four board types side by side, labelled CPU-S, PSU, VDI, VDO, shot on a neutral background. Alternatively an exploded view of a populated subrack.
Generic Product, Generic Application, Specific Application.
Three EN 50128 and EN 50129 terms that decide what you buy, what you build and what you certify. Most confusion about this product starts here.
Generic Product
Re-usable across independent applications. GMX-CS is one, and it is certified as one.
Generic Application
Built on the Generic Product, re-usable across a class of applications with common functions. Yours.
Specific Application
One installation, with its site-specific data. Also yours.
NEAT / GMX-CS / BOARD SETFour boards.
- CPU-S — the safety computer, hosting nodes A and B running the GeminiX-OS application and implementing the GeminiX-Cores engine in FPGA
- PSU — power supply management, one or two boards, configurable
- VDI — vital digital inputs, also taking external sensor inputs such as an odometer
- VDO — vital digital outputs, safe state defined as the de-energised low state
The number of VDI and VDO boards is configurable from zero to nine in any combination, at different field voltages such as 24 V or 110 V. Both PSU and CPU-S can be redounded for availability.
What GMX-CS does not include.
Stated early, because it is the most common source of misunderstanding in a first technical meeting.
Because its boards can be mounted in several configurations, GMX-CS includes no physical connection device between them. The Generic Application provides a backplane, which carries the internal inter-board connections and exposes the external interfaces. Boards defined by the Generic Application, such as a communication computer or an external power supply board, can be hosted on the same backplane.
What you still own
- The backplane and the mechanical integration
- The Generic Application and the Specific Application
- The safety-related application conditions exported by the platform
- The safety case, site acceptance and approval
The design is stated to have been made with particular attention to component obsolescence management, in order to extend the product lifecycle as far as possible. For a rail buyer this sentence is worth more than a page of adjectives.