FEATURES

• HBT is a Bit Error Rate Tester for testing synchronous modems and other DCEs.

• HBT operates at data rates from 32 kbps to 2.048 Mbps, including 1.544 Mbps, and supporting all n x 56 kbps and n x 64 kbps data rates.

• When testing a DCE, a loop is performed, sending the data back to HBT. HBT compares the received pattern with the transmitted pattern and presents the result on an LCD display, counting bit errors, sync loss number, block errors and error-seconds. HBT also features an INJECT ERROR push button which enables the user to check the tester and the line by introducing errors in the transmitted data stream.

• Five test patterns are available: 511 pseudo-random, 2047 pseudo-random, 7 space 1 mark, 7 mark 1 space and alternating mark/space. Block size can be set to 512 bits, 1000 bits, 1024 bits, 2048 bits and 10 kbits.

• HBT can generate its own clock or receive clock from the connected DCE.

• HBT supports the following interfaces: V.35, X.21, RS-530, RS-232, G.703-2048 Mbps, G.703-1.544 Mbps and G.703-64 kbps by means of field-replaceable modules (see Ordering). Module replacement is straightforward and simple.

• Setup and operation are initiated from the front panel using soft keys and interactive menu selection on an LCD message display. Ten LED indicators display the activity of the interface signals.

• HBT is supplied in a convenient hand-held case. It is powered by a detachable external power supply unit.

FEATURES

The LBT is a Bit Error Rate Tester for testing synchronous or asynchronous modems and other DCEs. Testing can be conducted over full duplex or half duplex links. The LBT can also test modems connected in multipoint configuration for polling operation. A network with up to 32 slave modems is supported.

The LBT operates synchronously or synchronously at data rates from 75 bps to 38.4 kbps. When operating in synchronous mode, five test patterns are available: 511 or 2047 pseudo random, 7 space 1 mark, 7 mark 1 space, or alternating mark/space. In asynchronous and multipoint modes, only the 511 bit pattern is available.

When testing a DCE, a loop is performed, sending the data back to the LBT. The LBT compares the received data with the transmitted pattern and presents the result on an LCD display, counting bit errors, block errors and error-seconds. The LBT also features an INJECT ERROR push button which enables the user to check the tester and the line by introducing errors in the transmitted data stream.

Block sizes can be set to 512 bits, 1000 bits, 1024 bits, 2048 bits and 10 kbits. When testing multipoint, a block size of 512 bits is used.

The LBT can generate its own clock or receive clock from the connected DCE.

Set-up and operation are initiated from the front panel using soft keys and an interactive menu selection on an LCD message display. Ten indicator LEDs display the activity of the interface signals.

The LBT comes in a convenient hand-held case. The unit is powered by a detachable external power supply unit.

SPECIFICATIONS

• Bit error rate tester for sync or async links
• Data rates up to 38.4 kbps
• Point-to-point or multipoint
• Several test patterns
• Internal or external clocking
• Simple, straightforward operation

When the BERT is testing a synchronous device, a CCITT 511 pattern is transmitted. The BERT receiver verifies that the returning data is error-free, at which point the LED is lit.When in async mode, the BERT sends QUICK BROWN FOX messages and waits to receive the FOX messages back before illuminating the GOOD DATA LED. Flow control is achieved by using the CTS interface lead if you are testing DCE or the DTR interface lead if you are testing DTE. When the interface lead becomes inactive the BERT stops transmitting data.All power to operate the Pocket BERT is provided by the unit being tested—no external power supplies to carry around! Just drop the Model 55 BERT into your pocket and you are ready to troubleshoot anywhere.