Microtronix Systems Ltd. has developed an ISDN telephone testing capability as an option for its Model 500 Telephone Test System (TTS).

The ISDN Terminal Interface provides an S/T line Interface for the ISDN telephone under test. In conjunction with a Model 500 Telephone Test Set, manufacturers of ISDN telephones will now be able to perform high speed acoustic frequency response, loudness rating, dial tests, ringer tests, and BERT (Bit Error Rate Tests) under various simulated line conditions. The ISDN Tester is user configurable to test a wide range of features that are available on ISDN Telephones. Custom test scripts can be added by the user to meet present and future ISDN standards.

Acoustic Tests

The ISDN Terminal Interface allows the Telephone Test System to perform all of its standard acoustic tests on an ISDN phone. High quality audio tests are achieved through the use of an "ideal" CODEC.

Testing Capabilities

Parameters such as power consumption and bit error rate (BER) can be measured. All tests can be performed under various programmable power supply levels and line impairments. ISDN Transmission Line Simulation is included.


Since the ISDN world still contains proprietary Layer 3 implementations, the Microtronix ISDN Terminal Interface is programmable to accommodate changing test and protocol specifications. Either Microtronix or the customer can adapt the ITI to any Layer 3 protocol variation.

Modular Design

The ISDN Terminal Interface is a modular box which can be connected to your existing M500 Test System. Software updates are easily applied. New ISDN standards can be supported. Microtronix will work with its customers to help define the testing requirements of this new generation of telephones.

Telephony Tests

The following tests are available in conjunction with the Model 500 Telephone Test System:

  • Digital (D-channel) keypad verification.
  • Programmable D.C. Supply Voltage (PS1, PS2, PS3) with Current measurement and polarity reversal.
  • Transmit, Receive and Sidetone frequency responses and loudness ratings.
  • Audible B-channel DTMF frequency and amplitude.
  • Acoustic measurements of the ringer (Alerter) amplitude with programmable ringing patterns.