Abstract: A customizable data acquisition device (DA) and a data collection system (DCS). The DA is remotely located for attachment to a variety of I/O devices, and uses an RF transceiver with a primary cache. A centrally located or mobile DCS with a secondary cache communicates with one or more DA's and stores DA data in the secondary cache. The DA has a programmable controller and an I/O interface capable of attaching to a variety of I/O devices. The DA primary cache holds data for bulk transfers to the DCS to minimize DA/DCS data transmission traffic. The DCS secondary cache accumulates data from the DA and allows data queries by multiple independent application programs (which may be located on the DCS, other DCSs, or remote host systems) without requiring retransmission of data from the DA for each query. Applications can query cached data in the secondary cache, and optionally query the primary cache or query the I/O device via the DA.