Model 940A Timing System Analyzer

Model 940A Timing System Analyzer

Reads, analyzes, and sources IRIG-B. The comprehensive instrument for power substation timing.


Model 940A User Manual
Download PDF(2 MB) »

Model 940A Data Sheet
Download PDF(546 kB) »

Model 940A Timing System Analyzer is a comprehensive instrument for power substation timing. Intuitive and easy to use, the Model 940A is designed to simplify timing system installation and maintenance. Capable of measuring and sourcing IRIG-B, DCF77, and 1PPS timing signals, the Model 940A is a must have tool for substation timing systems.

The Model 940A uses two identical input channels capable of measuring IRIG-B (unmodulated, modulated and modified manchester), DCF77 and 1 PPS timing signals. The timing signals are decoded and displayed as text and/or graphically showing the complete timing signal down to the IRIG-B bit level. The dual inputs allow for comparison to a calibrated signal or between different signal generators. The Model 940A Timing System Analyzer is also equipped with an output that can source modulated IRIG-B, unmodulated IRIG-B, 1 PPS and DCF77. Output levels, modulation ratios, and the timing reference are configurable. The flexibility to synchronize the timing reference to Input 1, Input 2, the internal Real Time Clock, or a user customized setting makes the 940A suitable to test any timing scenario.

  • Two input channels.
  • One customizable source channel.
  • Measures:
    • IRIG-B unmodulated
    • IRIG-B modulated
    • IRIG-B modified manchester
    • DCF77
    • 1 PPS
  • Industrialized display glass protects the 800 x 480 color TFT capacitive touchscreen.
  • Long life lithium-ion battery
  • Built-in LED flashlight.

I/O Configuration

Output Connectors

One, BNC female

Output Signals

  • IRIG-B modulated
  • IRIG-B unmodulated
  • DCF77
  • 1 PPS

Level: 1 Vdc to 15 Vdc, 1 Vpk to 10 Vpk
Drive: 125 mA at 5 V
Time Reference: Input 1, Input 2, Real Time Clock, or User

Input Connectors

Two, BNC female

Input Signals

  • IRIG-B modulated
  • IRIG-B unmodulated
  • IRIG-B modified manchester
  • DCF77
  • 1 PPS

Level: 25 Vpk maximum
Impedance: selectable: high impedance, 50 ohms, or 100 ohms.



  • 800 x 480 color TFT capacitive touchscreen, backlit
  • Single or Dual Timing Signals
  • Data and/or Waveform

Real Time Clock: Reference to Input 1, Input 2, or User

Power Requirements



Internal Battery

  • Type: Li-ion (9000 mAh capacity)
  • Operation: 24 hours typical
  • Charge: 8 hours to 12 hours with unit off

External Power

  • Voltage: + 5 Vdc
  • Current: 1 A

Micro USB


Fashlight: Built in LED

Audio: Indicator tone (enable/disable)



204.7 mm x 166.5 mm x 48.5 mm (8.1 in x 6.6 in x 1.9 in)
381 mm x 305 mm x 229 mm, (15 in x 12 in x 9 in), shipping


0.6 kg (1.4 lbs), maximum
2.5 kg (5.5 lbs), shipping



Operating: - 10 °C to + 50 °C
Charging: 0 °C to + 45 °C
Nonoperating: - 40 °C to + 75 °C



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Click to Download Latest Version of Software
940_Utility_31Jul2017_0100 Uploads firmware


Software Version and Related Information

940 GUI Utility Software (940_Utility)

  • Compatible with Windows 7 and 10.
VersionRev LevelVersion Notes
31Jul2017 01.00

Initial release.

Firmware Information (EPROM based firmware is not available for download)
940_Firmware_31Jul2017_0101 Downloadable. Use the 940Utility to import file into unit.


Firmware Version and Related Information

Downloadable firmware upgrade (940_Firmware)

VersionRev LevelVersion Notes
31Jul2017 0101

Updates are not security related.

  1. Leap second fixes.
  2. Firmware upload more robust.
  3. Improved synchronization.
  4. Improved holdover.
  5. Allow local offset in 30 minute increments.
  6. Fixed One Second Compensation.
  7. Many other improvements and enhancements to better serve your needs.

IRIG-B Time Code Accuracy, IED and System Design Issues
Download irig_accuracy_and_connection_requirements.pdf (31 kB) »

IRIG Standard 200-16
Download irig-b_200-16.pdf (857 kB) »

IRIG-B Specifications
Download irig_b_spec_brief.pdf (488 kB) »

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