VCL-2705, GPS Receiver and Time Distribution Unit


The VCL-2705, GPS Receiver and Time Distribution Unit is a low cost and high-performance GPS Receiver with multiple IRIG-B outputs which provides sub-microsecond accuracy. The VCL-2705 is designed to provide 1 x IRIG-B (BNC) output, 1 x IRIG-B RS-485 (differential pair with multi-drop capability to support up to 16 RTUs) and 1 x RS-232 (twisted pair) output. Unit also provides one external dry relay alarm contact.

The relay has a rating of 5 Amps (amperes) and a maximum 250V DC, which can be connected to an external alarm such as a piezoelectric buzzer or an DC powered (LED) lamp and can be wired up for either NO or NC contact.

The VCL-2705 is a compact and cost-effective solution to provide 3 commonly used variants of IRIG-B outputs to make it suitable in any application which requires an IRIG-B time input. This solution is designed to work in harsh environment including outdoor control enclosures. Exceeds IEEE C37.90 and IEC protective relay standard for robustness.

Data Sheet GPS Receiver and Time Distribution Unit

Suitable for Utility applications, relay event correlation and other high-accuracy timing requirements. Un-Modulated IRIG-B outputs with +100 ns accuracy meet requirement for existing and future timing applications.

Block Diagram

Features and Highlights

  • 1 x 1 PPS Out (50 Ohms BNC)
  • 1 x IRIG-B Unmodulated coaxial cable output (50 Ohms BNC- Female)
  • 1 x IRIG-B Unmodulated differential pair output (RS485, 2 PIN connector)
  • 1 x IRIG-B Unmodulated twisted pair output (RS232, 2 PIN connector)
  • <100ns Accuracy when locked with GNSS (GPS or GNSS option)
  • 12V ~60V DC Power Supply input
  • 1 x 3-pin (NO, NC & COM) External Dry Contact Alarm and Control Contact.

Technical Specifications

Core unit / Chassis

Input / Output Interfaces Number of Interfaces Connector
GPS or GNSS (GPS + GLONASS) Input Interface 1 TNC
Input Power Supply (12 ~ 60V DC) 1 2 Pin DC Power Connector
1PPS Out 1 BNC (Female)
IRIG-B (Un-modulated) Output - 50 Ohms coaxial Interface 1 BNC (Female)
IRIG-B (Un-modulated) Output - RS485, differential twisted pair interface 2 2x4 PIN Terminal with GND
IRIG-B (Un-modulated) Output - RS232, twisted pair interface 1 2 PIN Terminal

GPS/GNSS Receiver Specifications:

  • 50 Channel GPS Receiver/ 72 Channel GNSS Receiver
  • GPS L1 frequency, C/A Code Receiver
  • Tracks up to 12 / 24 satellites in GPS /GNSS mode
  • Synchronizing Time: Hot Start (1 sec.), Warm Start (28 sec.) and Cold Start (28 sec.)
  • GPS Signal: Tracking and Navigation: -162dBm
  • Accuracy of Time-Pulse Signal referenced to GPS: +/-30ns
  • Accuracy of Time-Pulse Signal referenced to GNSS: +/-20ns
  • Automatic Leap Year Correction and Learning

Antenna Specifications:

  • Antenna Type: Active
  • Frequency Band: 1575.42MHz
  • Amplifier Gain: 38dB (supports up to 50 meters of LMR 240 antenna cable)
  • VSWR:<2.0Max, 1.0 Typical
  • Operating temperature: -20°C to +60°C

Synchronization Inputs:

  • 1 x GPS (TNC)


  • DIN Rail Mounting. Ruggedized Aluminum Chassis.

EMI, EMC, Surge Withstand and other Compliances:

  • CISPR 32 / EN55022 Class A (Conducted Emission and Radiated Emission)
  • IEC 61000-4-2
  • IEC 61000-4-4
  • IEC 61000-4-5
  • Immunity to Voltage Dips, Short Power Supply Interruptions and Voltage Variations meets and exceeds IEC 61000-4-11, Level 1 specifications
  • Complies with FCC Part 68 and EMC FCC Part 15 Class A
  • Telcordia GR-1089 Surge and Power Contact.

Electromagnetic Standards Compliance:

  • IEC 61000-6-2 (immunity)
  • IEC 61000-6-4 (emission)

Regulatory Compliance:

  • RoHS
  • CE Marking
  • Complies to IEEE and IEC standards
  • Transportation ETS 300 019 Class 2.3

Data Sheet

Data Sheet