Solid state recording current meter conversion

Last generation recording current meters used various types of magnetic tape as data recording media that were invariably the major source of error and/or the reason for loss of data. New generation recording current meters have turned to solid state devices as data storage media. This paper describes the conversion of an Endeco-174 current meter to a solid-state recording current meter. A removable solid-state module was designed to fit in the space originally occupied by an 8-track tape cartridge. The module contains a CPU and 128 kilo-bytes of nonvolatile CMOS memory. The solid state module communicates with any terminal or computer using an RS-232C interface at 4800 baud rate. A primary consideration for conversion was to keep modifications of the current meter to a minimum. The communication protocol was designed to emulate the Endeco tape translation unit, thus the need for a translation unit was eliminated and the original data reduction programs can be used without any modification. After conversion, the data recording section of the current meter contains no moving parts; the storage capacity of the module is equivalent to that of the original tape cartridge.