Description
Scitec SATD4 D4/ESF Rackmount T1 Modem DS1 RS-232 RS422 V.35 110V 60Hz
The Scitec SATD4 is a 1U rackmount T1 modem supporting both D4 and ESF framing formats on a DS1 network interface. It provides multiple data interface options — RS-232, RS422/449, and V.35 — making it flexible for a range of DTE equipment. Front-panel toggle switches handle framing, timing, and loopback configuration, while a dedicated status LED array monitors loop, power, data, and network conditions including BPV, DCD, CRC, and RED indicators. An alarm terminal block on the rear provides Minor and Major alarm outputs for integration with external monitoring systems.
Specifications & What's Included
- Make / Model: Scitec SATD4
- Type: D4/ESF Rackmount T1 Modem
- Form Factor: 1U Rackmount
- Power: 110V AC, 60Hz, 0.375A
- Fuse: 250V, 0.375A, Slow-Blow (IEC fuse holder)
- AC Inlet: IEC C14 (rear panel)
- Framing Modes: D4, ESF (toggle switch selectable)
- Line Coding: AMI, B8ZS (toggle switch selectable)
- Timing Modes: Master, Loop (toggle switch selectable)
- Loopback Modes: Local, Line, Remote Up, Remote Down
- Network Interface (J3): DS1 Line — DB15 connector
- Station Clock Interface (J4): RS422 — BNC connector
- ESF Channel Data Interface (J5): RS-232 — DB25 connector
- NRZ Data Interface (J6): RS422/449 — DB37 connector
- V.35 Interface: present on rear panel (NRZ data interface area)
- Alarm Output (TB1): 6-position terminal block — Minor (positions 1–3) and Major (positions 4–6)
- Front Panel Status LEDs: LOOP RMT/ACT, PWR/CLK, DATA, BUFF, BPV, DCD, CRC, RED
- Front Panel Controls: Reset (MSTR/ALM), Framing (D4/ESF), Line Code (1's/None, AMI/B8ZS), Timing (MSTR/LOOP), Loopbacks (Local/Line, RMT UP/OFF/DOWN)
- UL Listed: 51C3 (Multiplexer)
- Included: Unit only; no cables or accessories
Applications
The Scitec SATD4 is a T1 channel service unit/modem designed to terminate a DS1 (T1) network line and provide framed data to DTE equipment via RS-232, RS422/449, or V.35 interfaces. D4 (also called superframe, or SF) and ESF (Extended Superframe) are the two standard T1 framing formats used on North American digital carrier networks; the SATD4 supports both, allowing it to match whatever framing the network provider provisioned. Equipment of this type was widely deployed in the 1980s and 1990s at customer premises to interface leased T1 lines with data communications equipment — routers, multiplexers, videoconferencing codecs, PBX systems, and similar gear that required a clean framed T1 handoff. The multiple data interfaces (RS-232, RS422/449, V.35) made it compatible with a broad range of DTE devices that used different serial standards of that era. Loopback capabilities (local, line, remote) supported end-to-end circuit testing and fault isolation, a standard requirement in T1 provisioning and maintenance. Units like the SATD4 remain relevant in legacy telecom environments, government networks, and industrial installations that still operate DS1 circuits.
This Scitec SATD4 D4/ESF Rackmount T1 Modem has been inspected and is in good used condition. It was pulled from a working environment where it was in active use. The chassis shows light surface wear consistent with rack service — minor scuffing on the top cover and front panel edges — but the controls, toggle switches, and connectors all appear intact and undamaged. The rear interface connectors (DS1 DB15, RS-232 DB25, RS422/449 DB37, V.35, and STN CLK BNC) show normal contact wear. Please view our photo set and contact us if you have any questions.
Warranty Information
Additional Information
Brand: |
Scitec |
Model: |
SATD4 |
MPN: |
SATD4 |
Type: |
D4/ESF Rackmount T1 Modem |
SKU: |
43083 |
Condition: |
Used – Pulled from Working Environment |
Form Factor: |
Rack Mount, 1U |
Power Requirements: |
110V AC, 60Hz, 0.375A |
Fuse: |
250V, 0.375A, Slow-Blow |
Protocol: |
D4, ESF |
Line Coding: |
AMI, B8ZS |
Interface Type: |
DS1 / T1 |
Network Connector: |
DS1 Line – DB15 (J3) |
Data Interface 1: |
RS-232 – DB25 (J5 ESF Channel) |
Data Interface 2: |
RS422/449 – DB37 (J6) |
Data Interface 3: |
V.35 (J6 area, NRZ Data Interface) |
Clock Interface: |
RS422 – BNC (J4 STN CLK) |
Alarm Output: |
TB1 Alarm terminal block – Minor/Major (6-position) |
Framing Modes: |
D4, ESF |
Timing Modes: |
Master, Loop |
Loopback Types: |
Local, Line, Remote Up, Remote Down |
Status Indicators: |
LOOP (RMT/ACT), PWR/CLK, DATA, BPV, DCD, CRC, RED |
Country/Region of Manufacture: |
United States |
Seller Notes: |
Unit only; no accessories included. Pulled from a working environment. |
Condition Notes: |
Scitec SATD4 D4/ESF Rackmount T1 Modem in good used condition. Inspected and pulled from a working environment where it was in active use. Light surface wear on chassis; controls and connectors intact. Please contact us with any questions. |
