Description
Racal-Datacom Excalibur ISX 5300 T1 Multiplexer DSU/CSU RS-232 V.35 LAN PBX
The Racal-Datacom Excalibur ISX 5300 is a standalone T1 multiplexer with an integrated DSU/CSU, designed to transport LAN, PBX, voice, and data traffic simultaneously over a single T1 (1.544 Mbps) line. Manufactured by Racal-Datacom Inc. of Sunrise, Florida, the ISX 5300 belongs to the Excalibur product family — a line of enterprise-grade T1 access and multiplexing devices built for WAN connectivity. The unit features a front-panel LCD display with dedicated Test, Function, and User sections for local monitoring and configuration.
Specifications & What's Included
- Manufacturer: Racal-Datacom Inc., Sunrise, FL (Made in USA)
- Model: Excalibur ISX 5300
- Type: Standalone T1 Multiplexer with Built-In DSU/CSU
- Data Rate: 1.544 Mbps (T1 full-rate)
- DTE Interfaces: 2 × RS-232 / V.35 ports (Port 1 and Port 2, rear panel)
- Network Interfaces: 3 × DS1 RJ ports (DS1A, DS1B, DS1C — rear panel)
- External Clock Input: BNC (EXT CLK — rear panel)
- Power Input: External power supply via DIN connector (rear panel)
- Front Panel: Backlit LCD display; push-button controls for Test, Function, and User modes
- Form Factor: Desktop / standalone enclosure
- Certifications: FCC Part 68 (Reg. No. APSUSA-20191-DE N), UL Listed, CSA Certified
- Applications: LAN bridging, PBX tie-trunk, voice, and synchronous data over T1
- Includes: Racal-branded external 25V DC power supply with DIN connector
Applications
The Excalibur ISX 5300 is a T1 inverse multiplexer and access device from the early-to-mid 1990s, the era when dedicated T1 leased lines were the backbone of enterprise WAN connectivity. Units like the ISX 5300 allowed organizations to consolidate multiple traffic types — voice calls from a PBX, LAN data, and synchronous serial data streams — onto a single T1 circuit, dramatically reducing the number of separate leased lines a company needed to maintain between sites. The built-in DSU/CSU eliminated the need for a separate Channel Service Unit/Data Service Unit at the demarc point, simplifying the CPE (customer premises equipment) footprint. The RS-232 and V.35 DTE interfaces connected directly to routers, bridges, and PBX systems of the era. The Excalibur series was widely deployed in corporate campus environments, branch office WAN links, and telecom carrier CPE applications. Today these units are sought by legacy network maintainers, telecom historians, and engineers supporting older PBX or synchronous serial infrastructure that still operates on T1 circuits.
This Racal-Datacom Excalibur ISX 5300 T1 multiplexer has been inspected and appears to be in good used condition. It was pulled from a working environment where it was previously in service. The front panel LCD display and push-button controls are intact with no visible damage. The rear RS-232/V.35 ports, DS1 RJ jacks, and EXT CLK BNC connector all appear clean and undamaged. The chassis shows light cosmetic wear consistent with normal use — minor surface scuffing on the top cover. The original Racal-branded external 25V DC power supply is included and shows normal wear as well. The bottom label is intact and legible, confirming FCC registration and UL/CSA certification. Please view our photo set and contact us if you have any questions. Please note: We have multiple units in stock — yours may not be the one shown in the photos, however, it will be similar in condition and function.
Warranty Information
Additional Information
Brand: |
Racal-Datacom |
Model: |
ISX 5300 |
MPN: |
Excalibur ISX 5300 |
Type: |
T1 Multiplexer with Built-In DSU/CSU |
SKU: |
11226 |
Series: |
Excalibur |
Interface Type: |
RS-232, V.35, T1 |
Connector Type: |
RS-232/V.35 (Port 1 & Port 2), DS1A/DS1B/DS1C (RJ), EXT CLK, PWR |
Number of Ports: |
2 x RS-232/V.35 DTE ports; 3 x DS1 network ports |
Data Rate: |
1.544 Mbps (T1) |
Protocol: |
T1 ESF/D4 |
Application: |
LAN, PBX, Voice, and Data over T1 |
Management Type: |
Managed — front-panel LCD display, network management options |
Form Factor: |
Desktop / Standalone |
Power Requirements: |
External power supply included (25V DC) |
Country/Region of Manufacture: |
United States |
Condition: |
Used – Pulled from Working Environment |
