PECA's RF Distribution Unit (Unit 1) is a subsection of PECA's Transmission Medium Impairment Simulator (TMIS) systems.

The RF Distribution unit is the heart of PECA's Standard TMIS systems. It provides the following:

• Independent RF I/O ports and level settings for Forward (downstream) and Return (upstream) test carriers.

• Switched test points in both the forward and return path.

• Means to connect test instrumentation to test points in the Forward and Return paths.

• Means to direct both forward and return test carriers through any of four independent physical transmission media

• Means to subject test carriers to independently generated forward and return In-Line impairments.

• Means to combine test carriers with additive independently generated forward and return impairments.

• An input port for a head end feed or multi-carrier generator

The RF Distribution unit is designed to be sufficiently flexible to permit easy and repeatable reconfiguration of test configurations. For example, it will provide any of more than 18 test configurations defined in the CableLabs DOCSIS Acceptance test Plan (ATP).

The RF Distribution Unit can be controlled either manually, via front panel controls or via RS-485 interface for computer and automated control.

The computer (automated) control is via two I/O boards which are internal to the RF Distribution unit and two PECA RS-485 SmartPlug Modules externally connected to the 25 pin D connectors on the I/O boards.

In a fully integrated test system, the PECA RS-485 SmartPlug Modules are daisy chained via RJ-11 modular cables between units. The chain is connected to an RS-232 to RS-485 converter on the RS-232 COM port of a PC or via PECA Unit 10.