The General Purpose Computer Interface (GPCI) provides an interface between a non-Honeywell computer and Honeywell Total Distributed Control (TDC 2000)
equipment via the Data Hiway.

The test panel plugs into the test logic board and can be removed without affecting on line operation.

Hiway Test Mode:
This mode exercises a major portion of the GPCllogic as if the control were coming from the host computer.
Commands and data are entered from a bank of switches. The Hiway logic performs the function selected and the results are displayed in a bank of indicator LED’s. The function can be performed single-step or continuously. The status word is also displayed.