Function and principle The user test CC08TSS board test switch user processing board Test subscriber system). user testing CC08TSS board completed with the host and terminal users within the perimeter loop trunk, the outside line and terminal testing, complete alarm collection and forwarding to complete the various environmental monitoring, and also provides serial port for maintenance and veneer surveillance Print test bus interface for the docking of 112 test equipment. The development is aimed at improving the accuracy of the line test, test speed, failure to judge the accuracy of the test system stability, increase the new test function entry, to conform to the local network 112 concentration of the overall measurement system specification requirements ". the CC08TSS board modify the CC07TSS board, the main difference between the two is that the: selection logic devices optimization.