Posted to Tool & Equipment Forum on 1/16/2016
13 Replies
I bought an Autel Maxiscope MP408 from a member here a while
ago, and haven't had many chances to use it at work, so I
brought it home and scoped my broken TV remote. I learned a
little about the scope and software, thought I'd share.
There wasn't much info out there on them, except for the
horrible software and support.
First, some pros and cons. The pro list is very short. The
hardware specs are impressive. Strangely they are identical
to the pico 4423 scope specs (more on that later). Another
pro is the cost of the device. I jumped on a good deal, but
even full price is a decent price for what you are supposed
to get. If you are expecting tech support, or working
software, you may be disappointed though.
Now for the cons. The support is a joke. The autel mp408
forum is mostly people complaining about problems with the
software, and lack of responses from tech support. The few
official replies mention "we are working on it" and not much
else. There was probably a software team at some point, but
it looks like there is probably only one person now, or
possibly nobody working on it.
The software is very buggy. I can't comment on the android
software, as I could not get it to run at all on my tablet,
but I can talk about the PC software.
1. You can only record 1 screen of data. Once the screen is
full, all is lost, and it starts over from the beginning.
This is a huge problem.
2. Anytime a trigger is set, when the recording is stopped,
the whole program freezes and never recovers. This is a huge
problem.
3. At timebases of 200 ms/div and slower, the performance is
horrible, compared to published specs. There is something
wrong here, I don't think it is a hardware limitation, but
it is possible. Measurements can be seen in the first
figure.
4. Measurement functions (min, max, P-P, frequency, AC RMS,
etc...) are not able to be added after the waveform is
captured. They must be set up before the capture is started.
5. The trigger point indicator will sometimes disappear,
never to be seen again.
6. Intermittently, the zoom reset function will not work
correctly.
All of my problems, should be able to be fixed with software
changes. I'm not sure about the sample rate problem of 200
ms/div and slower timebases, but I would hope so.
At first glance of the spec sheet, it may seem like they
cloned a pico 4423, and wrote some crappy software to go
along with it. I am not sure. The maxiscope uses an altera
cyclone V FPGA part# 5cefa2f23c8n. I think I remember
hearing that pico uses xilinx FPGA's. There is no doubt that
autel studied the pico software when making their own. I am
not able to dig into the pc version, but the android package
is just a zipped file. Unpacking it and looking through
leads to a certain file, that inside makes many references
to different files ending with a .psdata and .hta extension.
I know pico uses psdata, and I believe also hta for scripts?
I believe these are for presets and scripts they planned on
using (stealing). Funny that they didn't even bother
changing the file extension. It seems so obvious. Oh well,
I'll leave that one for the lawyers to argue about.
First figure is the actual sample rates when using only 1
channel (or 2 if staggered, A+C or B+D)
[Maxiscope sample rates]
Second figure is example of zoom when using 20 ms/div
timebase.
[maxiscope 20ms/div sampling]
Third figure is example of zoom when using 100 ms/div
timebase.
[maxiscope 100 ms/div sample rate]
Last figure is example of zoom when using 500 ms/div
timebase. This is when the sampling rate drops off horribly,
as seen in the unreading zooms.
[maxiscope 500 ms/div sample rate]
It's hard to say whether or not to recommend this scope to
anyone. In my case it was a clear choice. I have wanted to
learn scope techniques for a long time, the shop does not
supply a scope for tech use, and was not interested in
purchasing one. When compared to the 2 scopes this is
replacing (a snap-on pac-pro scope from 1991 that is down to
1 working channel, and only works about 5% of the time, and
a cheapo $20 USB scope that only has a 0-5v range), this is
worlds of improvement. If only I didn't know what it should
be capable of, I might be happy.
Alan Maultsby
Technician
Alan Maultsby
Apex, North Carolina, USA