Abstract: Modular equipment for data acquisition/control of a system comprises a central unit (CPU Board), a plurality of input/output modules and a bus coupled therebetween. The central unit has successive approximation generator means (2) for generating a plurality of unique system addresses. The plurality of input/output modules each acquire information from/administering control of said system, and each of said plurality of input/outout modules is located at one of said unique addresses. The bus comprises an interrupt control line (IRQ) for requesting an interrupt service, whereon one or more of said plurality of modules periodically places an interrupt service request. Identifcation means, responsive to said successive approximation generator means (2), identifies an address of a module from which an interrupt service request emanated.