High speed signals are used for inter-module communications. These signals use LVPECL single-ended format. All the connections using the easy-phi high speed signals have a QMA connector on the module's frront panel.
All other signals should have a different connector. For example universal input modules have SMA connectors for their inputs and QA for their output signals (standardized format).
The high-speed signal standard allow for up to 1GHz signalling. Pulse lengths can be as little as 500ps:
To use LVPECL chips as single-ended the following termination has to be adopted: