Looking to add a new Logic Analyzer to my toybox
Jim Fouch
Posts: 395
I'm in a market for a new Logic Analyzer.
I currently have an Intronix LogicPort ( http://www.pctestinstruments.com/ ) I bought like 5-6 years ago and it has served me well. Only issue is it's pretty limited in the amount of samples it can take. It has 2048 samples / channel. For many things it works, but for some others it is way too limited. For example, if you're trying to debug a problem with a SPI bus and the issue is several packets from your trigger point, you are out of luck. There are a few ways to overcome this if you have control of the process that send the data, but if you're trouble shooting a closed system, there is no way.
I see that Saleae ( https://www.saleae.com/ ) has a new Logic Pro 16 that does not rely on dedicated memory at the device. It uses a USB 3.0 interface to stream data quickly to the PC and then the PC will work with the data. I've heard good things about Saleae, but I'm a bit worried that with out the hardware triggers and such it will limited. I have played with their software in demo mode and it's nice but somewhat basic when it comes to triggers.
In my search for another hardware based LA I came across this Logiczero ( http://www.amazon.com/dp/B002NBYRLM/ref=wl_it_dp_o_pC_S_ttl?_encoding=UTF8&colid=RL8MED0OEVIU&coliid=I3GY9Y6PY3LC1Y ) LAP-C 16 channel with 128K points per channel. That like 64 times what I have now. The bandwidth is not as high as my LogicPort, but I don't need 500MHz. I've never heard of Logiczero before, but their software looks pretty powerful for triggering and protocol decoding.
My budget is right around $500. I know I could get a real nice one for a ton of money, but I don't need all the bells and whistles.
I'm mostly looking at using this for double checking my software timing on things like the Propeller and PIC 8-bit and 32-bit processors. For interfacing to LCDs and such. I do think I need at least 16 channels, so one of the cheaper 8 channel units from Saleae will not work for my needs.
Any advice is welcomed.
I currently have an Intronix LogicPort ( http://www.pctestinstruments.com/ ) I bought like 5-6 years ago and it has served me well. Only issue is it's pretty limited in the amount of samples it can take. It has 2048 samples / channel. For many things it works, but for some others it is way too limited. For example, if you're trying to debug a problem with a SPI bus and the issue is several packets from your trigger point, you are out of luck. There are a few ways to overcome this if you have control of the process that send the data, but if you're trouble shooting a closed system, there is no way.
I see that Saleae ( https://www.saleae.com/ ) has a new Logic Pro 16 that does not rely on dedicated memory at the device. It uses a USB 3.0 interface to stream data quickly to the PC and then the PC will work with the data. I've heard good things about Saleae, but I'm a bit worried that with out the hardware triggers and such it will limited. I have played with their software in demo mode and it's nice but somewhat basic when it comes to triggers.
In my search for another hardware based LA I came across this Logiczero ( http://www.amazon.com/dp/B002NBYRLM/ref=wl_it_dp_o_pC_S_ttl?_encoding=UTF8&colid=RL8MED0OEVIU&coliid=I3GY9Y6PY3LC1Y ) LAP-C 16 channel with 128K points per channel. That like 64 times what I have now. The bandwidth is not as high as my LogicPort, but I don't need 500MHz. I've never heard of Logiczero before, but their software looks pretty powerful for triggering and protocol decoding.
My budget is right around $500. I know I could get a real nice one for a ton of money, but I don't need all the bells and whistles.
I'm mostly looking at using this for double checking my software timing on things like the Propeller and PIC 8-bit and 32-bit processors. For interfacing to LCDs and such. I do think I need at least 16 channels, so one of the cheaper 8 channel units from Saleae will not work for my needs.
Any advice is welcomed.
Comments
I went the way of the heavy iron...
I bought a used HP Agilent 16702a Logic analyzer on eBay.
for that amount you can probably pick up a 165**, 166** or a 167** model with a 16550 card, which has 96 channels and 4K samples.
(Mine has two 16550 cards, connected so that I get 8K samples instead of doubling the inputs)
A bit more and you could hit 1M samples.
If you're really lucky you might even find one with a 16533 or 16534 scope card in it.
(These usually go fast! The 34 is a 500MHz DSO card)
The big problem with these is that they're... well... big... and rather noisy.
Anyway, are you certain that it's a Logic analyzer you need?
Not a dedicated protocol sniffer?
One of my clients just threw out two nice $25,000 HP LAs just to clean house. Said they didn't think they'd use them. :-( These were the really nice ones that will watch the address bus and display your code as it watches what's going on.
If they'd handed them to a surplus dealer, they should have gotten at least $200 for each if they were in a reasonably complete order.
And if they'd taken the time to list them on eBay... Some of the 16500/16600/16700 models can go for $1000 EACH depending on condition and spec.
A single 16534a DSO card for them in working condition is worth $500!
Workshops and hobbyists specializing in analog stuff such as multi-stage amps love them because these cards can be linked. You can have 4 of these cards in one enclosure getting you up to 8 channels with the same trigger and timebase!
Doing PWM or AD?
Let it use the same trigger as a 16550 card or similar. Catch both the input and output of the circuit...
And with a 16522a card, you can smulate the digital part of a DA circuit.
(Or possibly store and replay traffic from an I2C bus. Haven't tried, so... )
Disassembly is a nice function...
(I think that requires extra SW which can no longer be obtained or installed. They shut down the licensing servers years ago)
Another function I once saw(probably also a commercial package) displayed the 64K memory map of an 8bit CPU as a grid, and marked each location with a light whenever the CPU acessed it, then let it slowly fade. Quite a nice way of spotting where specific subroutines and their data is stored.
Did I mention that they're networked?
And can be accessed using Telnet for running scripts?
Portable?
Well, there is a carrying handle on them... ;-)
I really need to start to really use the one I have...
Another problem is like you said, some of that older equipment/software can't be bought anymore. Once it's gone it's gone.
I decided to take a chance with the Saleae Logic Pro 16. They have a 180 day return policy and people seem to like them a lot. @ $500 it's not a cheap date, but for the speed and ability to grab tons of data it may complement the LogicPort I already have. They really are two different approaches. Both have their weak points and strong points.
I have the SX model and it works quite well.
http://redpitaya.com/?skip_intro=no
My preferred Logic Analyser approach uses edge-time-stamp capture, as that gives the best dynamic range and with rare events, you do not have the luxury of resetting ranges.
Edge-stamp also needs much lower transfer bandwidths.
Best specs:
Hantek LA5034, purchased about a year and a half ago for P2 development
http://www.hantek.com/en/ProductDetail_16_16.html
just over 2K samples, supposed to have RLL compression, which did NOT work for me a year ago, may have new firmware
Intermediate Price:
I have a LAP-C 16 with I think 64Mbit sample memory that I order a few months ago, have not really given it a workout yet.
Good price, use the most:
SeeedStudio Open Workbench Logic Sniffer
http://www.seeedstudio.com/depot/Open-Workbench-Logic-Sniffer-p-612.html
EXTREMELY handy & useful. So inexpensive I bought several, now can't live without them.
Propeller Based - limited sample buffer
Hanno's ViewPort
Steve's Propalyzer
Inexpensive, very limited:
Saelig 24Msps 8 bit & clones.
Old school:
Really old Tektronik, takes up half my workbench, don't use it.