Abstract: A remote data acquisition and communication system includes a plurality of collector devices including a radio transmitter, optionally a plurality of concentrator devices including a radio transmitter, a radio receiver and a memory, a plurality of controller devices including a radio transmitter, a radio receiver and a memory, optionally a plurality of data communications nodes coupled to corresponding concentrator devices via a first communications link, and a data management platform computer coupled to the data communications nodes or the next lower level of devices via a second communications link. The collector devices, concentrator devices and controller devices communicate with one another via RF communications, preferably a single communication channel at a single carrier frequency.

Abstract: An annunciator or similar system includes a plurality of field terminal blocks whose terminals are connected to the field wiring, the field terminal blocks removably fitting within handle terminal blocks. The handle terminal blocks are fixed to module circuit boards which removably fit in an elongated channel member and have along one of their edges a set of contact areas which make contact with terminals fixed on the bottom wall of the channel member. The terminals of the field terminal block are angled relative to the bottom of the block and are parallel to one another.