# TTC DS3 Interface Module # TTC DS3 Interface Module ## Key Features At A Glance - DS3 testing at 44.736 MHz ±100 ppm with both unframed T3 and framed (M13 or C-Bit) operating modes - Normal and test loopback operating modes for end-to-end and self-test configurations - 75-ohm unbalanced WECO 560A input and output jacks at DSX and high-level operating ranges - B3ZS line coding with rectangular output pulse per CB119 Table 8 and CCITT G.703 DSX levels - Logic error, BPV, and frame error insertion — single or at programmable rates (1E-5 to 1E-9 on FIREBERD 6000, 1E-6 on FIREBERD 4000) - Yellow alarm and Blue alarm (AIS) detection with dedicated front-panel indicators - Fixed (1111, 1100, 1010, plus 3- to 24-bit programmable) and pseudorandom (2^15-1, 2^20-1, 2^23-1) test patterns - Selectable fast and slow frame synchronization loss criteria for application-tuned resync behavior The DS3 Interface Module is a plug-in module that extends a host FIREBERD 6000 or FIREBERD 4000 communications analyzer with native DS3 (44.736 Mbit/s, T3) test capability. It provides DS3 transmit and receive interfaces, framing logic, pattern generation and detection, error insertion, and alarm monitoring — turning a FIREBERD analyzer into a complete DS3 bit error rate test set for North American digital hierarchy line and equipment testing. DS3 is the 44.736 Mbit/s level of the North American Plesiochronous Digital Hierarchy, historically carried over coaxial DSX-3 cross-connects in central offices and long-haul transmission systems and used to aggregate twenty-eight DS1 (1.544 Mbit/s) tributaries. Engineers and technicians install the DS3 Interface Module in a FIREBERD chassis to verify DS3 line cards, multiplexers, M13 and C-Bit framers, microwave radios, fiber terminals, and DSX patch panels, and to commission or troubleshoot DS3 spans by injecting known patterns and counting received errors at the far end or via loopback. ValueTronics International has specialized in test and measurement equipment since 1992, and our 20,000 sq ft secure warehouse at 1675 Cambridge Drive in Elgin, Illinois is where each instrument is received, inspected, and verified before it ships. Legacy DS3 test gear like this module is exactly the kind of equipment that benefits from a knowledgeable second-source supplier — the modules are no longer manufactured, the host analyzers remain in active service in carrier and defense network test labs, and finding a working unit with the right interface and framing options often comes down to inventory depth and condition documentation rather than a catalog page. ## Brand Heritage The FIREBERD product line — including the 6000 and 4000 hosts that accept this DS3 Interface Module — originated with TTC (Telecommunications Techniques Corporation), which became part of Dynatech Communications, then Acterna Corporation in 2000, then JDSU after Acterna was acquired in 2005, and finally Viavi Solutions after JDSU split its test and measurement business in 2015. Modules and analyzers bearing TTC, Dynatech, Acterna, or JDSU branding all trace through this same lineage. ## Product Core & Specifications Specification Value Framing Modes Framing T3 unframed; T3 framed (M13 or C-Bit) Operating Modes Modes Normal; Test loopback DS3 Input Input Connector WECO 560A jack Input Frequency 44.736 MHz ± 100 ppm Input Impedance 75 ohms nominal, unbalanced to ground Operating Range (HIGH Level) +6 dB to -26 dB of flat loss from nominal high level Operating Range (DSX Level) +6 dB to -26 dB of flat loss from nominal DSX level DS3 Output Output Connector WECO 560A jack Output Frequency 44.736 MHz ± 10 ppm Output Impedance 75 ohms nominal, unbalanced to ground Output Pulse (HIGH Level) Rectangular pulse Amplitude 0.91 peak ± 0.11 volt peak Width (at 1/2 amplitude) 11.2 ns ± 1.1 ns Rise/Fall Times (10%-90% amplitude) 4.5 ns ± 1.5 ns, overshoot -10% pulse amplitude DSX Level Per CB119, Table 8 CCITT G.703 Line Code B3ZS Error Insertion Logic Errors Single insertion or insertion at specified rate BPVs Single insertion or insertion at specified rate Logic and BPVs Single or rate Frame Single insertion of 1-15 consecutive frame errors Error Insertion Rates FIREBERD 6000 = 1E-5 to 1E-9; FIREBERD 4000 = 1E-6 Indicators Frame Sync DS3 frame synchronization achieved Code Idle signal received ALM1 Yellow alarm received ALM2 Blue signal received Alarm Criteria Yellow Alarm Detects a far-end out-of-frame condition (i.e., framing is lost) (X1 and X2 bits set to zero) Blue Alarm (AIS) “Keep alive” pattern detects complete system failure (C-bits=0 and 1000 bits of 1010 pattern) Signal Loss Signal Loss 0.02 ms without valid input pulses Patterns Fixed 1111, 1100, 1010, and 3- to 24-bit programmable Pseudorandom 2^15-1, 2^20-1, and 2^23-1 Pattern Synchronization Criteria Fixed Patterns 64 consecutive error-free bits Pseudorandom Patterns 60 + n consecutive error-free bits for length 2^n-1 Pattern Synchronization Loss Criteria Loss 1,024 errors per 32,767 bits Frame Synchronization Criteria Sync 15 consecutive error-free F bits and two consecutive error-free M0-M1-M0 sequences Frame Synchronization Loss Criteria Fast (selectable) 3 of 15 F-bits in error, or two of three M0-M1-M0 sequences in error Slow (selectable) 6 of 15 F-bits in error **Important:** Requires a FIREBERD 6000 or FIREBERD 4000 host analyzer for operation; the error insertion rate range depends on the host (1E-5 to 1E-9 on the FIREBERD 6000, 1E-6 on the FIREBERD 4000). **Important:** The DS3 Interface Module is a plug-in module that requires a FIREBERD 6000 or FIREBERD 4000 communications analyzer mainframe to operate; the mainframe is not included. **Important:** DS3 input and output connections use WECO 560A jacks; suitable 75-ohm unbalanced coaxial cables and adapters are required and not supplied with the module. **Please review the Manufacturer's Data Sheet to verify published specifications. Feedback on this webpage is always welcome — please reach out to your Test Architect at any time for questions or concerns. Thank you, we truly appreciate you being our customer.** ## Details - **Price:** 578.0 USD - **Vendor:** TTC - **Type:** Module - **Tags:** Accessories, Instek, Manufacturers, Other Equipment, product_manual_group_1, Product_new, Software ## Variants | Variant | Price | Available | |---------|-------|-----------| | Default Title | 578.00 USD | In stock | ## Images - DS3-PWR Instek Software --- > Source: [ValueTronics](https://valuetronics.com/products/ds3-pwr-instek-software-new) > Updated: 2026-05-25