1. Preface

1.1. Introduction

Congratulations on your choice of instrument. It will serve you well and give you today’s ultimate performance for many years to come, whether you work with advanced ultra-high resolution frequency analysis in R&D, high-precision calibration in Metrology, or high speed testing of time & frequency in test systems.

Your instrument is the industry’s first bench-top multichannel frequency counter/analyzer designed to bring a new dimension to bench-top and system frequency counting and analysis. It gives significantly increased performance compared to traditional Timer/Counters. The CNT-104S offers for example the following benefits:

  • 4-parallel time-stamping input channels, means you have 4 independent frequency counters in one box. An enormous save of money and space in test systems
  • Phase-compare 4 stable frequencies continuously in real time in a time metrology lab, without the need for external signal switching
  • The parallel-channel time-stamping design, where all channels run on the same time scale, allows to measure Time Interval with multiple stop channels, which is very valuable for exact timing of one-shot events
  • Graphical intuitive User Interface, with large 5” color touch-screen control
  • Easy control of instrument via mouse or web interface.
  • Up to 13 digits of frequency resolution per second and up to 7 ps resolution/timestamp
  • A high measurement rate of up to 20M readings/s to internal memory
  • Optional oven-controlled timebase oscillators,Choice of RF prescaler options with upper frequency limits ranging from 3 GHz to 24 GHz
  • Integrated 1Gbit Ethernet and USB interfaces with SCPI commands support

1.1.1. Powerful and Versatile Functions

In addition to the traditional measurement functions of legacy timer/counters, these instruments have a multitude of other functions such as Multi-stop Time Interval, Phase, Duty factor, rise/fall time, Slew Rate, TIE (Time Interval Error), Totalize and Peak Voltage. The CNT-104S introduces the concept of parallel measurements, for example 4 frequency measurements in parallel, or one rise time plus one fall time measurement in parallel on the same pulse. Even on single-shot pulses!

By using the built-in mathematics and statistics functions, the instrument can process the measurement results on your benchtop, without the need for a controller. Math functions include inversion, scaling and offset. Statistics functions include Max, Min and Mean as well as Standard and Allan Deviation on sample sizes up to 32×106.

1.1.2. No Mistakes

You will soon find that your instrument is self-explanatory with an intuitive user interface. A settings menu tree with few levels makes the CNT-100 easy to operate. The large graphic LCD is the center of information and can show you several signal parameters at the same time as well as status.

Measurement samples are presented as numeric values, or graphically over time, to reveal signal stability, trends, or modulation. Stability information can easily be presented as value distribution or trend plots in addition to complete numerical calculation results like max, min, mean and standard deviation.

The Autoset function is available on any input waveform and can make best settings of the currently selected measurement function. Use the built-in web server interface or VNC to get an enlarged view of the front panel on your desktop or laptop PC, tablet or even mobile phone. You can control every setting, start & stop measurements, and even download measurement data.

1.2. Design Innovations

1.2.1. State of the Art Technology Gives Durable Use

These Analyzers are designed for quality and durability. The modern design with high integration and low component count reduces power consumption and results in an MTBF of 15,000 hours. A rugged mechanical construction, including a metal cabinet that withstands mechanical shocks and protects against EMI, is also a valuable feature. Rubber bumpers around the front panel further enhance ruggedness.

1.2.2. High Resolution

The use of reciprocal interpolating time-stamping counting, combined with a smart calibration algorithm, results in excellent resolution: <7 ps per time stamp or 12-13 digits/s in frequency measurements for all frequencies.

Timestamps of trigger events are taken continuously, and the frequency values are calculated on the fly, while the set measurement is running without interruption in the background, thereby assuring gap-free zero-dead-time measurements between samples. Minimum time between calculated values is 50 ns, meaning a sampling speed of 20 MSa/s.

1.3. Remote Control

This instrument is programmable via Ethernet (ETH) or USB interfaces.

The ETH is the primary interface intended for use in test systems, on lab benches, and fully remote control and monitoring from “anywhere in the world”.

The web interface and VNC server are included, which gives you an exact copy, pixel by pixel, of the instrument’s screen. All instrument settings can be controlled from the web interface or VNC, and result data can be read.

In test systems, the CNT-104S uses the standardized SCPI language for programming the instrument’s functions and reading the results.
The USB interface is mainly intended for the lab environment with the “remote” controller in a nearby place.

1.3.1. Fast Data transfer over remote interfaces

The bus transfer rate is up to 200 measurements/s for individually triggered measurements, and 170k measurements/s in block transfer mode. Array measurements to the internal memory can reach 20M measurements/s.

This very high measurement rate makes new measurements possible. For example, you can perform jitter analysis on several tens of thousands of pulse width measurements and capture and transfer them in less than a second.

The 4-channel parallel frequency measurement architecture significantly improves measurement speed, compared to using 4 separate frequency counters, and individually addresses them in a sequence.

The CNT-104S also features data streaming “forever” of gap-free measurements. This means you could leave CNT-104S in a field site, either connected to a local PC or connected to a local network, to monitor e.g., 4 different synchronization signals for a week or two and come back and collect tons of gap-free data for analysis.

Programmer’s Handbook helps you understand SCPI and the Analyzer’s programming. Complete counter settings can be stored and can easily be recalled on a later occasion.

2. Safety

2.1. Introduction

Please take a few minutes to read through this part of the introductory chapter carefully before plugging the line connector into the wall outlet.

This instrument has been designed and tested for Measurement Category I, Pollution Degree 2, in accordance with EN 61010-1:2011, and CSA C22.2 No 61010-1-12 (including approval). It has been supplied in a safe condition. Study this manual thoroughly to acquire adequate knowledge of the instrument, especially the section on Safety Precautions hereafter and the section on Installation.

2.2. Safety Precautions

All equipment that can be connected to line power is a potential danger to life. Handling restrictions imposed on such equipment should be observed.

To ensure the correct and safe operation of the instrument, it is essential that you follow generally accepted safety procedures in addition to the safety precautions specified in this manual.

The instrument is designed to be used by trained personnel only. Removing the cover for repair, maintenance, and adjustment of the instrument must be done by qualified personnel who are aware of the hazards involved.

The warranty commitments are rendered void if unauthorized access to the interior of the instrument has taken place during the given warranty period.

2.3. Caution and Warning Statements

CAUTION: Shows where incorrect procedures can cause damage to, or destruction of equipment or other property.

WARNING: Shows a potential danger that requires correct procedures or practices to prevent personal injury.

2.4. Symbols

Shows where the protective ground terminal is connected inside the instrument. Never remove or loosen this screw.

This symbol is used for identifying the functional ground of an I/O signal. It is always connected to the instrument chassis.

Indicates that the operator should consult the manual.

Personal safety is ensured when the input signal level is below 30 Vrms (when accidently touching the input signal lead)

Damage level for the input decreases from 350 Vp to 12Vrms when you switch the input impedance from 1 MΩ to 50 Ω.

Measurement BNC cables length shall be kept below 3m.

Circuits of external devices connected to BNC sockets, USB sockets and Ethernet sockets should be separated from the power supply network (and from other sources of dangerous voltage) at the level of reinforced insulation.This separation should not be confused with the permissible voltage of the external signal, including the voltage of 350 Vp referred to in the manual. If the equipment is used in a manner not specified by the manufacturer, the protection provided by the equipment may be impaired.

2.5. If in Doubt about Safety

Whenever you suspect that it is unsafe to use the instrument, you must make it inoperative by doing the following:

  • Disconnect the line cord
  • Clearly mark the instrument to prevent its further operation
Fig. 1‑1 Do not overlook the safety instructions!
  • Inform your Pendulum Instruments representative.

For example, the instrument is likely to be un­safe if it is visibly damaged.

2.6. Disposal of Hazardous Materials

There are no batteries or other potentially hazardous materials included.

You should dispose of your worn-out Frequency Analyzer, after a long and happily life, at an authorized recy­cling station or return it to Pendulum Instruments.

3. Unpacking

Check that the shipment is complete and that no damage has occurred during transportation. If the contents are incomplete or damaged, file a claim with the carrier immediately. Also notify your local Pendulum Instruments sales or service organization in case repair or replacement may be required.

3.1. Check List

The shipment should contain the following:

  • Multi-channel Frequency Analyzer CNT-104S Line cord
  • Printed version of the Getting Started Manual Brochure with Important Information Certificate of Calibration
  • Options you ordered should be installed. See Identification below.

Note: To ensure always up-to-date user documentation, the user manual (this document) is not included on any media in the shipment. Instead, the user documentation can be read on-line or downloaded as PDF from manuals.pendulum-instruments.com

  • Getting Started User’s Manual
  • User’s Manual
  • Programmer’s Handbook

3.2. Identification

The type plate on the rear panel shows type number and serial number. Installed options are listed under the menu About, where you can also find information on firmware version and calibration date.

3.2.1. CNT-104S configuration guide

Product code (12NC): 9446 101 04XYZ

 CNT-104S is configured using factory installed HW options, and customer installable options via SW license keys. The 12NC code only describes the HW configuration. SW enabled options and built-in measurement apps are coded separately, and not shown in the HW configuration 12NC code

X = RF/Microwave frequency option
0 = None
1 = Not used
2 = Reserved
3 = Reserved
4 = Reserved
5 = Reserved
6 = 3 GHz (Option 10)
7 = 10 to 24 GHz CW (Option 110, SW upgradable from 10 to 24 GHz)
8 = Reserved
9 = Customer special

Y = Oscillator option
2 = TCXO (standard oscillator in CNT-100, New)
5 = OCXO, High stability (Option 30, same as for CNT-9x)
6 = OCXO, Ultra-high stability (Option 40, same as for CNT-9x)

Z = Rear panel inputs and other HW options
1 = standard
2 = rear inputs A, B, D, E and C (Option 11/100)
3 = Reserved
4 = Reserved
5 = Reserved
6 = Reserved
9 = Customer special

3.2.2. CNT-104S configuration guide – Options and Accessories

Product code for ordered SW licenses (12NC): 9446 101 XXXYY

XXX/YY = Main option / Version. NOTE: the first “X” cannot be a 0

110 group – Prescaler frequency upgrade
110/15 = upgrade from 10 to 15 GHz CW input C SW
110/20 = upgrade from 15 to 20 GHz CW input C SW
110/24 = upgrade from 20 to 24 GHz CW input C SW

130 group – Enable HW inputs/outputs
132 = Enable Pulse output SW

150 group – Enable measurement functions
151 = Enable TIE measurements

3.3. Installation

3.3.1. Supply Voltage


The Analyzer may be connected to any AC supply with a voltage rating 100-240 VAC 50-60 Hz (Nom.). The Analyzer automatically adjusts itself to the input line voltage.


The secondary supply voltages are electronically protected against overload or short circuit. The primary line voltage side is protected by a fuse located on the power supply unit. The fuse rating covers the full voltage range. Consequently, there is no need for the user to replace the fuse under any operating conditions, nor is it accessible from the outside.

CAUTION: If this fuse is blown, it is likely that the power supply is badly damaged. Do not replace the fuse. Send the Analyzer to the local Service Center.

Removing the cover for repair, maintenance and adjustment must be done by qualified and trained personnel only, who are fully aware of the hazards involved.

Removing the cover for repair, maintenance and adjustment must be done by qualified and trained personnel only, who are fully aware of the hazards involved.

The warranty commitments are rendered void if unauthorized access to the interior of the instrument has taken place during the given warranty period


3.3.2. Grounding

Grounding faults in the line voltage supply will make any instrument connected to it dangerous. Before connecting any unit to the power line, you must make sure that the protective ground functions correctly. Only then can a unit be connected to the power line and only by using a three-wire line cord. No other method of grounding is permitted. Extension cords must always have a protective ground conductor.

CAUTION: If a unit is moved from a cold to a warm environment, con­densation may cause a shock hazard. Ensure, therefore, that the grounding requirements are strictly met.

WARNING: Never interrupt the grounding cord. Any interruption of the protective ground connection inside or outside the instrument or disconnection of the protective ground terminal is likely to make the instrument dangerous.

3.3.3. Orientation and Cooling

The Analyzer can be operated in any position desired. Make sure that the air flow through the ventilation slots at the side panels is not obstructed. Leave 5 centimeters (2 inches) of space around the Analyzer.

3.3.4. Fold-Down Support

For bench-top use, a fold-down support is available for use underneath the Analyzer. This support can also be used as a handle to carry the instrument.

Fig. 1-2 Fold-down support for comfortable bench-top use.

3.3.5. Cleaning of the instrument

When cleaning the instrument, wipe it with a silicone cloth or soft cloth to remove dust or dirt. When it is hard to remove the dirt, wipe it with a cloth wet with water and dry the instrument completely after cleaning.

CAUTION :Never use any organic solvent such as benzene, acetone, etc.

3.3.6. Rackmount Adapter – one unit

Fig. 1-3 Dimensions for rackmounting hardware.

If you have ordered a 19-inch rack-mount kit for your instrument, Option 22/90 for one instrument, it has to be assembled af­ter delivery of the instrument. The rackmount kit consists of the following:

  • 2 brackets, (short, left; long, right)
  • 4 screws, M5 x 8
  • 4 screws, M6 x 8

WARNING: Do not perform any internal service or adjustment of this instrument unless you are qualified to do so.

Fig. 1-4 Fitting the rack mount brackets on the Analyzer.

3.3.7. Assembling the Rackmount Kit (Option 22/90)

  • Turn the device upside down
  • Remove the rubber feet in the plastic stand
  • Loosen the screws underneath the rubber feet
  • Remove the plastic stands
  • Remove the rubber bumper around the front
  • Remove the four decorative plugs that cover the screw holes on the right and left side of the front panel.
  • The long bracket in Option 22/90 has an opening so that cables for Input signals can be routed inside the rack.
  • Mount the rackmount kit with the included screws

3.3.8. Reversing the Rackmount Kit

The instrument may also be mounted to the right in the rack. To do so, swap the position of the two brackets.

3.3.9. Rackmount Adapter – two units

This rackmount adapter can hold any two standard Pendulum ½ x 19” unit, like FDA-301A, CNT-9x, CNT-10x, GPS-12x etc.


If you have ordered the Option 22/05 rack-mount kit for two instruments, it has to be also assembled after delivery of the instrument. The rackmount kit consists of the following:

  • 4 Brackets, rear
  • 1 Hinge Spring Latch
  • 2 Ear, rack
  • 1 Assembly instruction, SXS Rack kit
  • 2 Screws M4x8
  • 8 Screws M5x10
  • 1 Spacer M4x16

3.3.10. Assembling the Rackmount Kit (Option 22/05)

  • Turn the devices upside down
  • Remove the rubber feet in the plastic stand
  • Loosen the screws underneath the rubber feet
  • Remove the plastic stands
  • Remove the rubber bumper around the front
  • Remove the four decorative plugs that cover the screw holes on the right and left side of the front panel.

Use the following steps to complete the side by side rack mount installation for your products. If necessary, refer to the item numbers in the following diagram for additional detail.

  • Determine where you would like each unit positioned (i.e., on the right or left side)
  • If plugs exist on the mounting holes on the front left and right side of product cover, remove and discard them
  • Using screwdriver, screw the rack ear (Item #2) into place using the supplied 10mm screws (Item #5)
  • Pinch the hinge pins together to separate the right and left hinge halves (Items #3 and 4)
  • Attach hinge halves to the unit with hinge facing towards the front (as displayed in diagram)
  • Using a screwdriver, remove the existing rear brackets on the back of each unit
  • Using existing machine screws removed in previous steps, attach the rear brackets supplied with the mounting kit (Item #1)
  • Pinch the hinge pins together into the stored position. Align the hinge halves together between the two units, and swing together side by side. The hinge pins should snap into place securing the front of the two units together
  • Take the supplied Hex Spacer (Item #7) and place between middle rear brackets, and secure using the supplied 8mm screws (Item #6)
  • Assembly is now ready for installation into standard 19” rack
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