PECA's Return In-Line Impairment Unit (Unit 15) is a subsection of PECA's Transmission Medium Impairment Simulator (TMIS) systems.

PECA's Return In-Line Impairment provides the means to route a signal carrier through four In-Line Impairments. Typical In-Line Impairments are:

• AM Noise                         

• Tilt

• Group Delay

• EXPAN (User Defined)

The Tilt, Group delay and EXPAN are individually selected and controlled in .5, 1, 2, and 4 dB step resolution by dip switches accessible from each units rear panel.

AM Noise:

Am Noise is produced by routing the test carrier through PECA's voltage controlled analog attenuator.

The AM Noise attenuator is driven by a Wavetek Model 395 Arbitrary Waveform generator.

Tilt, Group Delay and EXPAN:

Tilt, Group Delay and EXPAN are introduced via external modules connected to Input/Output ports for each In-Line Impairment, on the rear panel of the In-Line Impairment unit.  Note:  EXPAN is the designation for an un-designated In-Line Impairment.

PECA can provide the In-Line Impairment modules as defined by end user.

The Return In-Line Impairments 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 an I/O board which are internal to the Return In-Line Impairments unit and a PECA RS-485 SmartPlug Module externally connected to the 25 pin D connector 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.