TruePulse is seeking to purchase NT3A39AD and NT3A52AD circuit boards for the Nortel DMS-1U.

The NT3A39AD, HECI code SLCGCFA, DMS-1U OFC RPTR/PWRG is a Ringing generator.  The remote concentrator terminal (RCT) uses the NT3A39 ringing generator, which supports single-party 20 Hz ringing and multiparty coded ringing.

The NT3A52AD, HECI code SLCGCFA, is a Generator for the Nortel DMS-1U.

The DMS-1U, or DMS-1 Urban, is one of the types subscriber loop concentrators for the Nortel DMS-100.  The SCM-100U provides a digital interface between the DMS-100 and the remote terminal (RT) of the DMS-1U system. The term RT is used to describe the DMS-1U in its stand-alone configuration (also called the universal configuration). The term remote concentrator urban (RCU) is used to describe the DMS-1U when it is fully integrated into the DMS-100 switch (the SCM-100U is the peripheral module that integrates the DMS-1U into the DMS-100 switch).

The DMS-100 ringing system performs automatic number identification (ANI) and coin functions. The DMS-100 ringing signal is based on a 6-second (s) cycle. The cycle is divided into 12 time slots, which are the smallest divisions of the ringing cycle. The duration of each time slot is software controlled and is typically set to 0.5 s. In many DMS-100 peripherals, the ringing cycle is further divided into larger divisions consisting of one or more time slots. The DMS-100 line module equipment (LME), line concentrating equipment (LCE), and Subscriber Carrier Module (SCM) each use a distinctive ringing cycle format. For example, each subdivides the ringing cycle differently. The ringing cycle in the LME is divided into 12 time slots, which are typically set to 0.5 s each. The ringing cycle in the Line Concentrating Module (LCM), like the LME, is also divided into 12 time slots. However, the LCM ringing cycle is further divided into four subcycles. The subcycles consist of one or more time slots. The ringing cycle in the SCM, like the LME and LCM, is divided into 12 time slots. It is further subdivided into three phases consisting of four time slots of 2s each.

Ribbon Communications, who inherited the DMS platform through the Genband aquistion, no longer supports the DMS-1U.

In addition to the NT3A39AD and the NT3A52AD, TruePulse is interested in other Nortel DMS-1U and DMS-100 circuit boards.  In fact, we are interested in circuit boards for other legacy voice switching systems too including the Lucent 5ESS, the GTE GTD-5 and the Ericsson VSE.  Please let us know about any Class-5 voice switching equipment that you are planning to decommission.  We will buy your equipment outright, or sell for you on consignment.