An integrated coincidence system for multi-particle detection has been built to validate the coincidence detection and synchronize the readout of several pixel detectors. A system of two and also four detectors was built for measurements of angular correlations of rare fragments in ternary and quaternary fission which are detected in coincidence with the binary fragments. The pixel detectors are operated with the readout interface FITPix which provide power, control and DAQ. FITPix provides in addition signal communication ports and extended operability for the pixel detectors and the Timepix device (such as widely adjustable internal clock, external clock, clock gating, etc.), enables advanced triggering and high frame rate (up to 40 fps). The whole measurement can be triggered by a single event. An integrated analog spectrometer based on the USB 1.1.2 readout interface equipped with devoted module is used to provide a trigger from the common sensor signal of one pixel detector. The coincidence unit then monitors, validates and synchronizes the readout of the digital data. All operation and DAQ are managed by the modular software package Pixelman. The whole system can operate in vacuum and can be configured and extended into more detectors for a wide range of particle coincidence physics experiments.