cronologic FAQ

General

product choice

I have no idea whatsoever which measuring card is suitable for my application. Can you advise me on this?

We would be happy to assist you in selecting a board for your application.

For this purpose we need the following information:

How many measurement channels are needed?

What is the required time resolution?

Do you want to measure the area, intensity or shape of the pulse? Or is the time of occurrence sufficient?

Do you prefer a PCIe CEM card housed in a PC, or do you prefer an external device connected to a Thunderbolt / USB4 port?

Are you aiming for the most space-efficient data acquisition integration possible?

Regarding your timeframe, are you only interested in products that are available now, or are you also interested in upcoming products or custom solutions?

The best way would be for you to use one of our inquiry forms and fill it out completely.

Hardware

TTL signals

Are cronologic TDCs able to generate TTL or similar signals to synchronize other devices such as lasers, switches, etc.?

All cronologic TDCs that have the "TiGer function" offer this option. You can find more detailed information on this in our user guide for the corresponding device.

specific connection formats

Are cronologic measurement boards also available with optical inputs, BNC/SMA or SMB connections or with additional converters?

For some of our major customers, we currently offer solutions with SMA connections as part of special developments. Depending on the desired measuring card, it might be quite easy to find such a solution for you as part of a custom design.

We can also implement other connection formats as part of custom designs for larger product volumes.

However, suitable adapter cables may also be available on the market.

Please let us know your exact requirements and the intended quantities so that we can take care of the matter.

PC configuration

Is there a recommended PC configuration for use with these measuring boards?

As virtually all reasonably up-to-date PCs will run with our measurement cards, we do not provide any explicit details in this regard. Writing the memory contents to your PC does not require particularly high performance. Rather, the performance requirements of the computer used are determined by the application software used.

size of jitter

What size is the jitter of the cronologic TDCs?

Jitter refers to the deviation in the time it takes for data to arrive at each time window. It is often assumed that the jitter is at the FWMH value of 2 bins. This is not the case with our TDCs, as here jitter is not the limiting factor. Double-pulse resolution, on the other hand, is an important specification for most applications and is the limiting factor in terms of resolution. However, this is not directly related to the jitter of our measurement cards, as the jitter of our TDCs is significantly smaller than the bin size. Accordingly, the RMS error is so small that we do not consider it to be significant.

See also: bin-size, jitter, and RMS

input level

In which level should the signals I use range, which I feed to the inputs of the measuring cards?

Please refer first and foremost to our information in the User Guide for the respective product. The following technical specifications are subject to change without notice.

  • Our standard TDCs are AC coupled. The DC base line can be between 0V and 5V for these devices. Short positive and negative pulses with an amplitude of up to 5V can be processed. The discriminator threshold can be set between -1.32V and 1.18V relative to the DC baseline, with a step size of 40 µV. In general, the threshold voltage should be set well above the noise level of the input signal.
  • The inputs of our standard ADCs are AC-coupled single-ended analog inputs. The maximum input voltage is 0.5 V and the input impedance is 50 Ω. The analog offset can be between -0.25 and +0.25 V.

xHPTDC8 dead time

What has to be considered regarding the dead time respectively the input frequency of the xHPTDC8-PCIe?

The term dead time refers to the time lag or time offset that can occur when measuring with a TDC. The dead time specified in technical data of TDCs and the input frequency refer to the same parameter and are directly dependent on each other. An input frequency of 200 MHz, for example, corresponds to a double pulse resolution of 1/5 ns.

The extent to which this value is relevant for your measurement depends on the sensors used. Only in case the dead time of your sensors is extremely small and a high resolution is required, this value will be relevant for you.

The xHPTDC8-PCIe measures exclusively with the high resolution of 13 ps. In case incoming pulses are closer than 5 ns, only one pulse is detected.

constant fraction discriminator

Do the cronologic measurement cards offer an integrated CFD (Constant Fraction Discriminator)?

Since our measurement boards are designed for a wide range of applications, we do not integrate CFDs into our standard models. In principle, however, it is of course possible to operate our boards with external CFDs, which is also done by many of our customers. The threshold function (threshold comparator) is in most cases already sufficient to pre-sort the pulses on the input side. This is because the digital threshold is adjustable for each input and can alternatively be configured for positive or negative pulses. Please refer to the operating instructions for more information.

In case extremely high demands are made regarding the comparator, an external device may be used.

bin size, jitter and RMS

How are bin size, jitter and RMS error related?

The bin size, jitter, and RMS measurement error are all important parameters that play a role in the digital acquisition of time data.

  • The bin size refers to the width of the time windows into which the data is divided during the measurement. The smaller the bin size, the higher the temporal resolution of the measurement. However, if the bin size is too large, there may be an overlap of data between each time window, resulting in an inaccurate measurement.
  • Jitter refers to the deviation in the time it takes for data to arrive at each time window. When jitter is high, data in a circuit can be erratic or inconsistent, resulting in an inaccurate measurement. Jitter is not directly related to bin size and therefore cannot be calculated directly from it. Jitter can be considered as the measure of the temporal variability of the acquired signal edges.
  • The RMS measurement error refers to the average deviation between the actual values of the input data and the values generated by the measurement. The lower the RMS measurement error, the more accurate the measurement.

xTDC4 dead time

What has to be considered with regard to the dead time respectively the input frequency for the xTDC4?

The term dead time refers to the time lag or time offset that can occur when measuring with a TDC. The dead time specified in technical data of TDCs and the input frequency refer to the same parameter and are directly dependent on each other. An input frequency of 200 MHz, for example, corresponds to a double pulse resolution of 1/5 ns.

The extent to which this value is relevant for your measurement depends on the sensors used. Only in case the dead time of your sensors is extremely small and a high resolution is required, this value will be relevant for you.

On each channel, about 5 ns after a previous hit, the xTDC4 is ready to measure a new hit with full temporal resolution. If the hits are closer together, the second hit is measured with a lower resolution (of 833ps). The start at the xTDC4 can come at arbitrary times as long as the distance to the previous start is at least ~300 ns.

TimeTagger dead time

What has to be considered with regard to the dead time respectively the input frequency for the TimeTaggers?

The term dead time refers to the time lag or time offset that can occur when measuring with a TDC. The dead time specified in technical data of TDCs and the input frequency refer to the same parameter and are directly dependent on each other. An input frequency of 200 MHz, for example, corresponds to a double pulse resolution of 1/5 ns.

The extent to which this value is relevant for your measurement depends on the sensors used. Only in case the dead time of your sensors is extremely small and a high resolution is required, this value will be relevant for you.

The TimeTagger measures start and stop with the same resolution and bandwidth. Thus, starts at the distance of the double pulse resolution are also handled correctly - the dead time thus corresponds to the double pulse resolution in practice.

common start

What is the key feature of a common start TDC?

Common Start TDCs, such as our TimeTagger or the xTDC4 provide a list of time stamps relative to a common start signal. This means the timestamps reflect the time difference between the start signal and the pulse measured on another TDC channel. The start signal must temporally precede the pulses being measured.

delay function

What are the capabilities of the delay function of the TimeTagger's input signals?

The user can implement user-defined delays on the measured time stamps in the software of the TimeTaggers. The input signals can be shifted with 200ps resolution in a range of approx. 200ns.

The xTDC4-PCIe features no input delays. However, after the common start group has been formed by the hardware, your software can implement any delays for the events present in the group.

Continuous Mode

Are cronologic TDCs able to record a continuous data stream over several hours?

Please note:

  • The xHPTDC8-PCIe provides an infinite stream of timestamps - one for each input channel.
  • The current TimeTaggers and TDC modules offer a Continuous Mode, and the measurement is not limited in time. In this mode, the device continuously records stop signals even without a start signal connected. The data stream periodically contains packets with an absolute 64-bit timestamp, followed by a list of stops relative to this timestamp. The period of the timestamps can be customized to fit the used evaluation interval. The config.tdc_mode parameter is used for this purpose, which switches between grouping and continuous. Only grouping is supported, so that the evaluation of the data stream in continuous mode is performed by the evaluation software used. In this case, the measuring card provides packet timestamps with ascending identifiers so that all packets can be evaluated accordingly.
  • The xTDC4-PCIe, on the other hand, is based on a classic common start architecture in which the arrival times of pulses at the "stop" inputs are measured relative to a signal at the "start" input. The duration of the recording is therefore limited in time.
  • The TDC channels of the Ndigo6G-12 all work in continuous mode to optimally complement the ADC measurements.

Please also note: The previous generation TimeTaggers (TimeTagger4-1G and TimeTagger4-2G) do not offer Continuous Mode.

multiple TDC channels

How does the use of multiple input channels affect the performance of my card?

The data acquisition of our TDCs is based on PCIe DMA. Thereby the maximum utilization of the data rate will in some cases only be reached if solely one measuring channel is used. In our technical data you will find the readout rate, which describes the maximum value and also the readout rate for the use of individual channels.

You are welcome to explain your application to us in detail, so that we can work out together how you can exploit the performance of our product to the maximum.

TDC synchronization

How many cronologic TDCs can be operated synchronously?

Just like the predecessor model HPTDC8, the xHPTDC8-PCIe also provides the option of synchronization when using multiple TDCs. The sync can take place via a total of 24 channels. A 10 MHz signal is used for the synchronization. Other cronologic TDCs such as TDC modules or TimeTaggers currently do not offer a direct synchronization option.

ADC integration

How can I integrate cronologic ADCs into my measurement setup?

Our ADCs are currently integrated exclusively via their PCIe interface.

TDC integration

How can I integrate cronologic TDCs into my measurement setup in a reasonable way?

In addition to using the PCIe interfaces of our measurement boards, the integration of our TDC modules can be considered for the TimeTaggers. The TDC modules are connected to your board via board-to-board connectors, using differential input signals for your analog front end. We will be happy to provide you with detailed information in this regard.

Alternatively, before purchasing an xTDC4-PCIe respectively TimeTagger, consider supplementing the TDC with our TBT2PCIe enclosure, which allows data transfer via USB4 using conventional Thunderbolt cables.

The xHPTDC8-PCIe is integrated exclusively via its PCIe interface.

pulse width measurement

Do TDCs only provide the arrival time of incoming pulses or also the pulse width?

Since the pulse amplitude is not measured when using TDCs, in many applications a derivation of the pulse intensity from the pulse width comes into question. In these cases, it may be useful to measure the pulse width as well as the arrival time of the pulse. For the acquisition of single photons, however, this is usually not necessary.

The measurement of pulse widths (i.e., a simultaneous measurement of falling and rising pulse edges) is feasible in most cases, but the specifics depend on the type of card in use.

  • The cronologic TimeTaggers are optimally suited for capturing the arrival time in conjunction with the pulse width. They provide (if enabled) timestamps of both the rising and falling edges of the measured pulse. The time difference corresponds to the pulse width.
  • Pulse width measurement is also possible with the xTDC4-PCIe, though it is more involved.
  • The integrated TDCs of the Ndigo5G-10 and the Ndigo6G-12 are also capable of capturing both edges of the pulse.
  • The xHPTDC8-PCIe captures only one edge per pulse, so the pulse width cannot be obtained with this device.

TiGer

What exactly is the function of the TiGer (timing generator)?

To use inputs to output arbitrary periodic pulse patterns for controlling your setup, you can write your own software that allows exact measurement of the timing of these patterns with the TDC. The TiGer can be used to measure exact timing differences between the generated output signals and various input signals on other channels. This is useful for a variety of applications.

The TiGer functionality can be configured independently for each port. Each TiGer may connect its output to the corresponding LEMO port. This turns the port into an output. The TiGer is DC-coupled to the connector. Connected hardware must not pass signals to the ports used as outputs, as this could damage both the TDC and the external hardware.

For this purpose, each digital LEMO-00 input can be used as an AC-coupled trigger output, whereby the TiGer functionality can be configured independently for each connection. This converts the relevant connection into an output. A bidirectional mode allows this output to be used consistently as a measurement channel if required. Unipolar or bipolar pulses may be used.

Firmware

firmware updates

Is it possible to update the firmware of my cronologic product by myself?

Yes, a corresponding program for updating the firmware is part of the driver package for our cards. Caution: Each firmware update requires a new calibration of the card using the provided calibration software. In some cases, it is necessary to provide appropriate input signals for this purpose.

Drivers

driver download

Where can I find the appropriate driver for my cronologic product?

On the pages containing product information, there is a corresponding tab. Plus on this website, all downloads for our products are listed. This also applies to products that are no longer in our current range.

For Linux support please use this page.

Software

software integration

With the measurement cards, do you offer software that can display histograms, count rates, coincidences, etc. with controlled time windows such as counts/s or counts/ms?

No. As our customers' requirements for evaluation software are very application-specific, they prefer to program their evaluation software and are happy about the lower hardware costs. Histogramming and other analysis of the timestamps can be programmed by the user with a few lines of code. We provide a C API that can be used to receive a stream of timestamps in almost any programming language.


In case you are active in research, e.g. in the field of atomic physics, we can put you in touch with partner companies that offer our products in a package with software packages.

MATLAB

Is it possible to use the cronologic DAQ boards with MATLAB based software?

We provide a C API that can be used to receive a stream of timestamps in almost any programming language. Histogramming and other analysis of the timestamps can be programmed by the user in a few lines of code.

We do not provide a separate interface to MATLAB. Basically, our drivers are intended to be used either directly in C/C++ programs or, when used in other languages, with a C/C++ wrapper that provides the driver's functions in the respective language and converts the data to the respective data format.

Matlab probably offers several ways to use C++ classes. This seems to be a viable way, although it is not trivial.

Another possibility is demonstrated here.

By the way: For basic applications that are rarely called, there is another way to solve the problem as the driver of our measuring cards offers a tool which records the data into a .csv file. This can then be analyzed in MatLab or also Excel. However, the amount of data generated is quite large, so you have to make sure in your own code that the data is really processed in real-time.

golang

Is it possible to use the cronologic DAQ boards with Go based software?

We provide a C API that can be used to receive a stream of timestamps in almost any programming language. Histogramming and other analysis of the timestamps can be programmed by the user in a few lines of code.

We do not provide a separate interface to Go / Golang. Basically, our drivers are intended to be used either directly in C/C++ programs or, when used in other languages, with a C/C++ wrapper that provides the driver's functions in the respective language and converts the data to the respective data format.

Julia

Is it possible to use the cronologic DAQ boards with Julia based software?

We provide a C API that can be used to receive a stream of timestamps in almost any programming language. Histogramming and other analysis of the timestamps can be programmed by the user in a few lines of code.

We do not provide a separate interface to Julia. Basically, our drivers are intended to be used either directly in C/C++ programs or, when used in other languages, with a C/C++ wrapper that provides the driver's functions in the respective language and converts the data to the respective data format.

LabView

Is it possible to use the cronologic DAQ boards with LabView based software?

We provide a C API that can be used to receive a stream of timestamps in almost any programming language. Histogramming and other analysis of the timestamps can be programmed by the user in a few lines of code.

We do not provide a separate interface to LabView. Basically, our drivers are intended to be used either directly in C/C++ programs or, when used in other languages, with a C/C++ wrapper that provides the driver's functions in the respective language and converts the data to the respective data format.

Rust

Is it possible to use the cronologic DAQ boards with Rust based software?

We provide a C API that can be used to receive a stream of timestamps in almost any programming language. Histogramming and other analysis of the timestamps can be programmed by the user in a few lines of code.

We do not provide a separate interface to Rust. Basically, our drivers are intended to be used either directly in C/C++ programs or, when used in other languages, with a C/C++ wrapper that provides the driver's functions in the respective language and converts the data to the respective data format. Wolfgang Löffler has created Rust bindings for our drivers. He has published code on GitHub under the Mozilla Public License that shows how to use TimeTagger4 and HPTDC8 with Rust. It should be easy to port this code to the xTDC4 and xHPTDC8 in case.

Linux

How can I use cronologic hardware most efficiently in Linux environment?

Our Linux-Supportweb page provides drivers and support for GNU/Linux based applications. ‍Please provide us with information about your application and the driver requirements for your Linux distribution and kernel version. Please note that only kernel versions from 5.0 (March 2019) are supported.

Python

Is it possible to use the cronologic DAQ boards with Python based software?

We provide a C API that may be used to receive a stream of timestamps in almost any programming language. Histogramming and other analysis of the timestamps can be programmed by the user in a few lines of code.

In principle, the use of Python based software is possible along with wrappers. Our customers write their own wrappers suitable for their particular application. For example, there is a Python wrapper for the HPTDC8.

Applications

non-sequential signals

Are cronologic TDCs also able to detect non-sequential or non-synchronized signals (i.e. random or emission signals detected by SPAD and not triggered by pulsed excitation), or can these boards only detect synchronized signals with an external source such as a pulsed laser?

Yes, such signals can also be detected. If this is not desired, the config.tdc_mode parameter can be used to switch between grouped and continuous measurement.

trigger

My product development respectively my experiment requires a trigger that I want to use as a start signal. Which TDC is best for me?

In this case, we recommend one of our Common Start TDCs, such as the xTDC4, TDC modules or one of our TimeTaggers.

infinite stream of timestamps

I want to capture an infinite stream of timestamps instead of time differences related to a common start signal. How can this be performed?

This function is not supported by the xTDC4-PCIe. Therefore, in this case we recommend using our xHPTDC8-PCIe, which has been optimized for this application. Our TimeTaggers and TDC modules offer a continuous mode, which allows continuous data recording.

ADC synchronization

How many cronologic ADCs can be operated synchronously?

When using one of our Ndigo Crates, up to eight Ndigo5G-10 cards can be mounted and operated in sync. The synchronization of Ndigo6G-12 is currently not possible.

defense

The company I work for is also closely associated with suppliers operating in the defense sector, or we produce military products ourselves. Is cronologic willing to supply us?

As part of our own sales policy, we would like to ensure that our products are not used in weapons systems. If you are considering purchasing our ADCs or TDCs, please let us know how you can ensure that the use of our products for military purposes can be reliably excluded.

Sales

ordering process

How exactly does the ordering process work at cronologic?

  • Usually, you will receive an informal message from us in advance of your order with the current prices of the requested items.
  • In case of interest, we will provide you with an official quote, in which any freight costs or insurance costs, etc. are also taken into account. If the desired item is in stock, we will schedule two weeks for final quality control, calibration, and preparation for dispatch.
  • As soon as we have received your order, we will send you an order confirmation. The item is thereby reserved for you. Please note: We observe international embargoes concerning individual countries, institutions and persons and reserve the right to carry out an export assessment in advance for each individual order, which may delay or prevent the implementation of the delivery.
  • In the next step, we carry out a final in-house check and calibrate the product.
  • Your invoice will only be issued when the goods are dispatched and your payment term is 14 days as standard. Depending on the selected shipping method, payment is therefore also possible after receipt of the goods.
  • You will receive your invoice by email and also with the shipment. Together with the invoice, you will receive the consignment note with the tracking number, which you can use to track the shipment if required.
  • Advice for urgent orders: Specifying the exact person who is to receive the goods can be helpful to ensure that the receipt of your goods is registered promptly. We will take this information into account when sending the goods.

formal quote

What do I need to do to get a formal quote?

Please provide us with the following information:

  • Details of the quantity of the desired cronologic products
  • if necessary, information about the desired delivery date
  • Your complete billing address and delivery address including the telephone number of your head office
  • If your billing address is in the European Union: Your VAT number
  • Your FedEx or UPS customer number. Please inform us immediately if you do not have one.
  • Information about your transport insurance. Please inform us immediately if you do not have one.

shipping insurance

Are the goods covered by insurance when they are shipped ?

We ship fully covered unless you specifically tell us that you have external insurance and therefore would not like us to do so.

shipments

How do we ship your goods?

We ship your goods via FedEx or UPS through your account. Thus you have full control over the shipping costs and can use your own conditions with the shipping company. In case you do not have a FedEx or UPS account, we will ship your order via our own UPS account and show the shipping costs separately on your invoice or within our offer. Please note that this procedure usually leads to significantly higher shipping costs. It is financially more worthwhile for you to open a new FedEx or UPS customer account - especially because you can then take advantage of the new customer offers of these shipping companies.

FCA incoterms

What does shipping to FCA Incoterms mean?

The International Commercial Terms are clauses for the interpretation of commercial contract standards. FCA (Free CArrier) is one of the clauses, which exclude the assumption of the costs for the main transport by the seller. In this case, cronologic takes over the handover to the carrier and, if necessary, also the customs declaration.

delivery restrictions

Are there any restrictions regarding the delivery of measurement cards to certain countries?

Our ADCs are classified as so-called dual-use goods, as they could be used for military purposes in addition to civilian applications. TDCs and Crates are not affected by these restrictions.

Regardless of the fact that we at cronologic want to exclude the use of our products for military purposes, the laws of the EU and many other countries restrict exports. Since we have to apply for a General Export Permit for these countries, delivery processes may be delayed or delivery to certain countries may become impossible.

For the application of this export license we need the following documents from you:

  • Exporter declaration
  • Company profile
  • Gegbf. import license (country dependent)

There are countries for which a general export license can be used for the export of dual-use goods. In this case we need documents from you and there will be no further delay:

These include:

  • Australia
  • Japan
  • Canada
  • Liechtenstein
  • New Zealand
  • Norway
  • Switzerland
  • Singapore
  • USA

export license

What documents are required to apply for an export license?

There are countries for which a general export license can be used when exporting dual-use goods.

In this case, we will need documentation from you and there will be no further delay:

These include:

  • Australia
  • Japan
  • Canada
  • Liechtenstein
  • New Zealand
  • Norway
  • Switzerland
  • Singapore
  • USA

As for other countries: To apply for an export license for dual-use goods we need the following documents from you:

  • Exporter declaration
  • Company profile
  • If applicable, an import license (this depends on the country of the importer.)

Please note: We observe international embargoes concerning individual countries, institutions and persons and reserve the right to carry out an export assessment in advance for each individual order, which may delay or prevent the implementation of the delivery.

goods dispatch

How long does it take to receive my ordered goods?

Provided that the ordered goods are products from our standard portfolio and are in stock, it can usually be assumed that the delivery will be dispatched within 14 days after receipt of the order. During this time, the item is subjected to a further detailed calibration and final inspection, packed and made ready for dispatch. Of course, it is always a requirement that all details regarding customs and shipping have been clarified in advance.

import permit

For which purpose is an import permit required and where can I get it?

Governments may impose certain restrictions on the imported goods as well as on their quantity. As a result, import licenses may be required. Such an import license is a document issued by a national government that allows certain goods to be imported into its territory. This is the international import document IC, which you may need to apply for at your customs office. Each import license specifies the quantity of imports allowed, and the total quantity allowed should not exceed the quota.

You need our export declaration to apply for an import permit.

Please find more information on the WTO website.

company profile

Why is a company profile needed and in what form can it be presented?

When trading dual-use goods, a company profile of the company to be supplied must be submitted to the German authorities. This company profile has to be created by you. It can be submitted in the form of company brochures, presentations, excerpts from the website or a self-representation on letterhead with company logo, letterhead or company stamp.

The purpose of this company profile for the authority is to prove the existence of the company as well as, if necessary, to make a prognosis decision on whether the goods are used in the civil or military sector.

It is mandatory to provide the complete address and communication data of your company and the company website. If your company is an affiliated company (such as a part of a holding company), a reference to this is helpful. Please describe the business activities of your company by listing all industries in which you operate and all product groups manufactured.

end-use statement

What is an end-use statement (EUS) and how do I fill out this document?

The end-user certificate (EUC) is a document in which the use of the goods for a specific purpose and, if applicable, the recipient country are documented. This applies exclusively to dual-use goods, such as our ADCs. The signature of the consignee on the end-use declaration is one of the prerequisites for the export of the goods in question. To ensure smooth processing of the shipment of goods, you should complete the designated form, if necessary, and preferably attach your official letterhead to it.

You will receive the necessary forms from us together with instructions on how to fill in the German End-Use Certificate. Further information can be found on the BAFA website.

Please note: We observe international embargoes concerning individual countries, institutions and persons and reserve the right to carry out an export assessment in advance for each individual order, which may delay or prevent the implementation of the delivery.

reseller

We are resellers and need sufficient margin for our services. Can cronologic help us with this?

As a matter of principle, yes, this is possible. In the run-up to our collaboration with companies that consider themselves resellers, we examine their business model in detail. This will take some time. Please provide us with comprehensive information about your company respectively your corporate group, your customers and the complete scope of your product range.

dual use

What is a dual-use item?

Due to their construction or design, dual-use goods can be used for both civilian and military purposes and are thus subject to the export control of the exporting country. The export of an item listed as dual-use usually requires an export license or a general export license from the responsible German authority. With regard to cronologic, this currently only applies to ADCs.

Please find detailed information on the BAFA website.

Please note: We observe international embargoes concerning individual countries, institutions and persons and reserve the right to carry out an export assessment in advance for each individual order, which may delay or prevent the implementation of the delivery.