I love my saleae Logic!
electromanj
Posts: 270
Hello all. I have been struggling with a serial communication problem lately, so I ordered a Logic Analyzer http://www.parallax.com/StoreSearchResults/tabid/768/txtSearch/logic/List/0/SortField/4/ProductID/743/Default.aspx.
I got it at around noon today. I wrote a small program to send various decimal commands and text strings from the Prop to an LCD. Very quickly I was able to see the commands that were sent and how fast they were happening.
Then I moved onto the problem at hand.
Problem: Able to send commands to a variable frequency drive, but not getting a response. Where was it going? Was I getting a partial response? Was I getting garbled response, or the wrong CRC? Was I even getting a response? Will the Cowboys ever have a game in the bag by the third quarter so I can relax? Who knows, and my Fluke can not give me the answer to any of these questions.
Solution: I hooked up two of the Logic's channels to the ttl side of my 485 to ttl converter and was able to determine that my query was arriving but I was getting no response back at all. With that information I was quickly able to discover that I had a bad connector. (db9 to terminal block). Since I had extra time on my hands now that the problem was solved I ran various other tests, took readings, and was having fun again instead of chasing my tail trying to "see" what is happening by trial and error.
Conclusion: On day one, this has already become one of those " how did I ever manage without it" tools.
I got it at around noon today. I wrote a small program to send various decimal commands and text strings from the Prop to an LCD. Very quickly I was able to see the commands that were sent and how fast they were happening.
Then I moved onto the problem at hand.
Problem: Able to send commands to a variable frequency drive, but not getting a response. Where was it going? Was I getting a partial response? Was I getting garbled response, or the wrong CRC? Was I even getting a response? Will the Cowboys ever have a game in the bag by the third quarter so I can relax? Who knows, and my Fluke can not give me the answer to any of these questions.
Solution: I hooked up two of the Logic's channels to the ttl side of my 485 to ttl converter and was able to determine that my query was arriving but I was getting no response back at all. With that information I was quickly able to discover that I had a bad connector. (db9 to terminal block). Since I had extra time on my hands now that the problem was solved I ran various other tests, took readings, and was having fun again instead of chasing my tail trying to "see" what is happening by trial and error.
Conclusion: On day one, this has already become one of those " how did I ever manage without it" tools.
Comments
You're positive experience has me really wanting one now!
Thanks e-manj!!
Gotta love the line from the first paragraph of the hardware description:
"If your Logic stops working for any reason, we’ll ship you a replacement at no cost, anywhere in the world."
My personal logic has failed me several times over the years.
Roger
Completely agree!!!
Having the a "wide view" of a debug situation is wonderful. And the reduction in frustration far outweighs the cost of the tool.
Congrats.
Check out the Saleae Logic 16.
Have a towel handy.
You're gonna drool.
@Roger Lee - was the magic smoke comment directed at me? LOL
ok, yes it was. no offense intended.
electromanj Please note that it goes up to 5 volt logic level. Don't you be hooking it up to your high power lines. ( see above)
(The Saleae Logic 16 Analyzer will be along side it. It's also a great module. Can't have too many of 'em)
Can't help but wonder why no one has come up with a unit that combines a scope, logic analyzer, and protocol analyzer. They all share quite a bit of common hardware.
Check out the USBee product line (www.USBee.com); they have such,
You'll pay for it though.