Abstract: An automatic call distribution and voice line PBX switching system which includes a control complex having a first microprocessor based control circuit to selectively establish connections between access ports of a switching network. The control complex further includes a second microprocessor based control circuit which communicates data with a group of automatic call distribution positions, each of which is coupled to a different one of a first group of the access ports. The first and second microprocessor based control circuits communicate asynchronously through an interprocessor buffer circuit, and the number of automatic call distribution positions served by both the first and second control may be selected depending upon the particular application for the system.

Abstract: An expandable modular control system with reduced memory requirements comprising an electronic data processing (EDP) system employing a microprocessor device and having gated program interrupt means. In particular, the expandable modular control system of the present invention comprises a "universal" microprocessor module which can be selectively combined with other separately packaged peripheral support modules to implement any particular control system required. Control point modules comprising a matrix array of flip-flops arranged as a plurality of n-bit words and subject to program control serve as extensions of the memory module to control the states of corresponding points in the system under the control of the modular control system. Sense point modules similarly organized in a matrix array monitor or sense the status of the points in the system under control and provide input data to the microprocessor module.

Abstract: A traffic analysis system is disclosed which utilizes a scanner to provide the identity of the trunk group within which a call attempt has occurred. The trunk group identity information from the scanner is supplied to a multiplexer which makes available four, 8-bit words based on the trunk identity information from the scanner. A micro-processor is coupled to the multiplexer and upon the occurrence of a call attempt the micro-processor adds the four words from the multiplexer, the sum of these words yielding the address of the proper storage location in a memory unit for storing the call attempt indication.