It is also a modular crate electronics standard commonly used in data acquisition systems in particle detectors.
Each module is typically a printed circuit board with a front panel, similar to a blade PC.
FASTBUS uses the emitter coupled logic (ECL) electrical standard, which allows higher speed than TTL and generates less switching noise.
This allows for very fast read-out of an entire segment by doing a chained block read from a master with a general-purpose CPU.
Crates typically have dedicated 200 A or 300 A switched-mode power supplies, providing current to the modules through multiple pins on the backplane connector.
Cooling and air handling are a significant issue, as is the safe design of high-current power distribution.
At the time, it seemed obvious that the way to get higher speed was a wide parallel bus, since the logic for each bit was already as fast as the electronics allowed.
These problems, together with the late development of inexpensive protocol chips, hindered the expression of the full potential of FASTBUS multi-segment architecture.