[en] The experience in designing the system for preliminary events selection for experiments on the SIGMA and GAMS spectrometers has been generalized. A unit-structure of the system allows one to use it efficiently in different experiments. Some real examples are given to illustrate the operation of the main units of the system. Some of the most typical circuit solutions are given. The main principle,he system based on, is synchronization of counter signals and strob-pulse, their state storage in triggers and subsequent analysis to take a decision on the event recording. To eliminate time synchronization the system in intermediate points is built according to the pulse-potential scheme. Natural is subdivision into three basic units-strob-pulse selection unit (strob-unit), detector signal recording units (recorders) and making decision units. The above division permits to use once constructed strob-unit and recorders in various experiments which reduces the time for designing the new system for preliminary events selection and costs for its design. The subdivision of the recording unit into few-functionally identical recorder-units allows one to synchronize various counter groups and provides the system with the required flexibility. The only unit constructed specially for the above concrete experiment is the making decisions units