Modem Processor Test Set (SEI)

Modem Processor Test Set (MPTS)

In early 1990, Squires Engineering, Inc. designed and implemented software for testing Modem Processors in Harris Government Systems' ACTS LBR-2 Earth Stations. LBR-2 Earth Stations are low-cost ground stations for communicating with the NASA Advanced Communications Technology Satellite (ACTS).

The Modem Processor Test Set (MPTS) software simulated predefined satellite TDMA downlink scenarios so that the hardware and software in the Earth Station modem processor could be exercise and validated.

MPTS software was comprised of the following components:

Scenario Description Language (SDL) - a test language was created for defining the timing and content of the frames of the simulated satellite downlink scenarios. The language also supported the display of messages to an operator console during testing.

SDL Compiler - an SDL compiler was designed to convert the SDL source statements into a compact p-code.

Integrated Development Environment (IDE) - the SDL compiler was integrated into a commercial text editor (BRIEF®) to allow SDL test programs to be quickly created, compiled, edited, run, etc.

Run Time Executive - a Run Time Executive was developed in 80386 assembly language to interpret the SDL p-code in real-time to control the MPTS hardware. Scenario p-code files were loaded into pages of EMS memory so that they could be fetched fast enough to allow the TDMA frame timing of each scenario to be accurately reproduced