What Is It?

The Model 404e is a hand-held combination E1 Digital, Datacom and Wideband Test Set
for the telecom field technician. It is a digital, full function 2.048Mbps E1/Datacom Tester,
as well as a full function analog transmission impairment tester. Uniquely designed with a
touch screen graphical user interface for extreme ease of use. It is about the size of a small
telephone book, weighs approximately 1-1/2 kilos and is powered by an internal
rechargeable NiMH battery pack with five to six hours of battery life. It comes standard
with a 115/230 VAC adapter or an optional 12 VDC cigarette lighter adapter. Analog and
DS0 tests meet ITU standards.
 

What Does It Do?

The digital test functionality of the Model 404e allows a wide range of bit error testing on
framed or unframed 2.048Mbps E1 circuits, and Datacom circuits, including V.35, RS232 and
EIA530. As an Analog Tester, the unit provides a wide variety of industry standard
measurements to accomplish transmission impairment testing on 2- or 4-wire dedicated or
dial-up analog circuits. With the Enhanced Digital option, an E1 telephone is added with
dial, talk & listen capability on any user selected E1 voice channel. The 400kHz bandwidth
of the instrument makes it ideal for qualifying metallic digital circuits which use an analog
carrier such as ISDN BRI ("U" interface) and 4-Wire HDSL circuits. The unit, of course, is
also ideal for qualifying voice circuits, which often will carry data modem and fax modem
signals.

How Does It Work?

The Model 404e is ideally suited for the field technician who must relate to all types of
digital and analog circuits. Datacom testing provides for emulating either the DTE or the
DCE while sending patterns and injecting errors.

What Can It Test?

As a Digital Tester two TX/RX ports are provided in order to allow bi-directional drop and
insert testing. The unit can terminate the line (simultaneous pattern generation and pattern
measurement) or monitor the line for BERT patterns, ABCD bit status, TS16 frame
synchronization and CRC errors. It is compatible with the unframed PCM, as well as PCM30
and PCM31 framing with HDB3 or AMI encoding.

As a Datacom Tester the extensive pattern generation and detection and the G.821 bit error
rate reporting are available for V.35, V.36, RS232 and EIA530 interface testing. The Model
402e acts as a synchronous DTE or DCE device and uses either the DCE clock or its
internal clock to generate and verify patterns at speeds ranging from 300 BP/S to
2.048Mbps.

The Enhanced Digital option provides VF testing of any user selected DS0 channel
including voiceband level, frequency, noise and return loss. Real-time error counters are
augmented by histograms so that the distribution of errors during a test can be studied. It
also provides a graphical display of pulse shape with the G.703 or a user set mask.

The Model 404e is able to perform AutoTesting with the Ameritec Model AM440 Remote
Test Partner™. The Model 404e is able to test analog measurements automatically with the
AM440 placed at the other end of the wire.