Abstract: A system comprises a plurality of first computing devices, wherein each first computing device is wearable by a user or is affixed to an asset within an environment and configured to generate and transmit a message; and a plurality of second computing devices installed within the environment, wherein a portion of the plurality of second computing devices are configured to detect at least one of the plurality of first computing devices, receive messages transmitted by a detected first computing device, and timestamp the messages before transmitting the messages to a computing server system. The computing server system is configured to determine at least a location of the detected first computing device based at least upon the messages received from the portion of the plurality of second computing devices.

Abstract: A unit for providing an interface between analog input signals and a digital data processing system bus includes a plurality of analog input channels, sample-and-hold circuits, and an analog-to-digital converter. An optical isolation circuit couples the output of the analog-to-digital converter to a dual-port RAM. The gain of each analog input channel is programmable, as is the address of each input channel in the RAM. Thus the channels can be read in any desired order, and different input voltage ranges can be programmed for each channel. The RAM can be read by an external data processing system via a digital system bus.