FAQ
General sigrok questions
What is sigrok?
sigrok is a portable, cross-platform, Free/Libre/Open-Source logic analyzer software that supports various logic analyzer hardware products. It is licensed under the terms of the GNU GPL.
What does the name sigrok mean?
sigrok is a logic analyzer software that groks signals for you.
What is the correct spelling of the name?
The name is spelled sigrok (yes, a lower-case "s", even at the beginning of sentences). It is not spelled "sigrock".
Is my logic analyzer supported?
Check the Supported hardware page for a list of supported logic analyzers, and those that are currently being worked on. Also, each device has its own wiki page, which lists the details of the hardware support for the respective device.
Will you add support for the XYZ logic analyzer?
Maybe. We generally try to support as much hardware as possible. However, as there are really many devices out there, this is of course a non-trivial task. We only have limited spare time, and a limited amount of money, too. Thus, naturally, we're happy about both code contributions as well as hardware donations (contact Bert Vermeulen and Uwe Hermann if you want to help out).
Do you build/sell/design logic analyzers?
No. The sigrok project is a pure (open-source) software project. We're not designing, building, or selling hardware. We only add software support for already existing logic analyzer hardware.
Which logic analyzer do you recommend buying?
We generally don't make any buying recommendations. There are many, many logic analyzers from different companies, with highly different capabilities and features out there, in price ranges from $60 up to $5000 or more. It all depends on your specific needs and preferences, and on the amount of money you are willing to spend.
However, as a small starting point for your own research in order to find a device which fits your need, we provide a Logic Analyzer Comparison table which lists some (but not all) relevant data points which you may want to compare.
Logic analyzer questions
What is a logic analyzer?
A logic analyzer is a device which can display and/or analyze the state of one or more signals of a circuit or target device. For a quick introduction see also the respective Wikipedia page, but make sure to read some of the documents from this entry for more details.
Where can I read more about logic analyzers?
Here is a list of recommended readings on various topics related to logic analyzers.
Note: Some of the Agilent/Tektronix documents are geared towards higher-end/expensive standalone logic analyzers, i.e. not the usual USB-based ones supported by sigrok. Thus, some of the information in those documents may not necessarily be relevant or important for most people. They do also provide lots of generally useful information, though, so reading them is recommended.
Introduction to logic analyzers:
- Tektronix: The XYZs of Logic Analyzers (PDF)
- EE Times/Agilent: A "How To" tutorial on logic analyzer basics for digital design
- Agilent: Application Note 1337: Feeling Comfortable with Logic Analyzers (PDF)
Samplerate, bandwidth, timing issues:
- EE Times/Agilent: How Much Bandwidth Does Your Logic Analyzer Need?
- Tektronix: The Importance of Timing Accuracy in a Logic Analyzer (PDF)
- Agilent: Application Note 1582: Logic Analyzer Specifications: How Much Timing Speed Do You Need? (PDF)
- Agilent: Reliable State Measurements on High Speed Buses (PDF)
- Tektronix: Fundamentals of Signal Integrity Primer (PDF, you need to provide some info before download)
Comparing or buying logic analyzers:
- Agilent: Application Note 1589: Evaluating Logic Analyzers Objectively (PDF)
- Janatek: F.A.Q: What to consider before buying a logic analyzer
Triggers:
Probing issues:
- Agilent: Application Note 1501: 6 Tips for Successful Logic Analyzer Probing (PDF)
- Agilent: Application Note 1450: Logic Analyzer Probing Techniques for High-Speed Digital Systems (PDF)
Other:
- Agilent: Application Notes: Logic Analyzer (list of documents)
- Tektronix: Logic Analyzer Tutorials (list of documents)
What kind of logic analyzer probes are available?
There are many logic analyzer probes of varying quality and price on the market (see photo for a small subset).
Probe collection.
Low-end probes
There are various simple and cheap logic analyzer probes available from various sources. Some logic analyzers are also shipped with this kind of probes out of the box.
They're generally not recommended, if you can avoid them. They're usually of low quality, break/bend/fail relatively quickly, and cannot be easily used to probe finer-pitch devices/pins. Probes 1 and 2 (see photos) also have the additional disadvantage that they're hardwired/soldered directly to a custom logic analyzer cable, which means they cannot be easily replaced, swapped, or removed and used for other purposes (which is possible with the other probes). See below for better alternatives.
Sometimes you can also replace the probes shipped with your device by a better-quality cable/probe set, e.g. in the case of the RockyLogic Ant8 probe cable (see photos).
Cheap probe 1.
Cheap probe 2.
Cheap probe 3.
Original Ant8 probe cable.
DIY Ant8 cable w/ EZ-Hooks.
Quality probes
The better-quality (and minimum recommended, in our opinion) probe type is the EZ-Hook. This type of probe is of sufficient quality, doesn't break too easily, and the grabber is small enough to probe most fine-pitch devices one usually encounters in day-to-day probing.
The Agilent probes (shipped with some Agilent oscilloscopes with integrated logic analyzer) seem to be exactly the same as the EZ-Hooks. They're probably merely rebranded for Agilent (just a guess).
The Tektronix probes are different, but of similarly good quality as the EZ-Hooks.
The ZEROPLUS probes seem to be custom-made by/for ZEROPLUS and are of similarly good quality, too (only one pin where you can attach, though; most other probe types usually have two).
Original EZ-Hook probe.
Agilent probe.
Tektronix probe.
ZEROPLUS probe.
High-end probes
There are of course also various higher-end, special-purpose probes which are much more expensive. They allow for probing much smaller pitch devices, for example.
Higher-end probe.
