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Products => Test Equipment => Topic started by: Kaziq on September 20, 2017, 08:50:34 am

Title: Optical cable from Brymen BM869 to Sanwa PC7000?
Post by: Kaziq on September 20, 2017, 08:50:34 am
Hi. I recently bought Sanwa PC7000 DMM, and then I found out it's the same as cheaper Brymen BM869. But I like Sanwa more, so it stays.

My question is: since they are apparently the same meter, will the PC optical cable from Brymen work with Sanwa? Its price is 1/3 of the Sanwa's, so it would be very nice if it did. I don't care if it won't hold physically, I can think of something, but would the protocol and software work fine? Has anyone got such set and can confirm it works?

--

A side-finding: I discovered that Sanwa is better than the manual says in one aspect. It retains 5 refreshes per second in hi-res mode, while manual and every page says it should drop to 1.25 per second.
I have asked the distributor about that, and they say they have tested the DMM, and the accuracy does not drop in hi-res mode, and is actually much better than the spec. So it looks like a nice surprise feature, not a bug.
Title: Re: Optical cable from Brymen BM869 to Sanwa PC7000?
Post by: wraper on September 20, 2017, 08:59:51 am
What do you mean by "it's the same"? These are 2 different meters, even if they happen to be based on the same chipset, which I doubt a lot, it won't fit mechanically.
Title: Re: Optical cable from Brymen BM869 to Sanwa PC7000?
Post by: Kaziq on September 20, 2017, 09:37:00 am
I mean:
- almost identical features and ranges,
- almost identical accuracy,
- almost identical range switch layout.

It's obvious one has been based on another. So perhaps the protocol is (almost) identical too?

I don't mind lack of mechanical fitness if the software side will work fine.
Title: Re: Optical cable from Brymen BM869 to Sanwa PC7000?
Post by: wraper on September 20, 2017, 10:21:12 am
It's obvious one has been based on another. So perhaps the protocol is (almost) identical too?
I have nothing to say except  :palm:
EDIT: and their specifications don't even match.
Title: Re: Optical cable from Brymen BM869 to Sanwa PC7000?
Post by: Kaziq on September 20, 2017, 10:34:07 am
Which specs don't match?

The only differences I see are 0.02% vs 0.03% base accuracy, and two temperature channels vs one.

Are you talking about a different DMM perhaps?
Title: Re: Optical cable from Brymen BM869 to Sanwa PC7000?
Post by: wraper on September 20, 2017, 10:36:07 am
Quiet a lot does not match. I searched more, Sanwa is based on same chipset. But optical interface is very different mechanically.
Title: Re: Optical cable from Brymen BM869 to Sanwa PC7000?
Post by: 2N3055 on September 20, 2017, 11:35:33 am
Quiet a lot does not match. I searched more, Sanwa is based on same chipset. But optical interface is very different mechanically.

With do all respect, I don't know about chip set, but optical interface (Sanwa KB-USB7) looks EXACTLY the same as the one for BM869...

Maybe electronics are different, but mechanically they look identical... Both USB dongle, and mating port on meter..
Title: Re: Optical cable from Brymen BM869 to Sanwa PC7000?
Post by: wraper on September 20, 2017, 01:46:55 pm
Quiet a lot does not match. I searched more, Sanwa is based on same chipset. But optical interface is very different mechanically.

With do all respect, I don't know about chip set, but optical interface (Sanwa KB-USB7) looks EXACTLY the same as the one for BM869...

Maybe electronics are different, but mechanically they look identical... Both USB dongle, and mating port on meter..
I looked on the pictures and there were quiet different. Maybe that was different angle some clone on the brymen pic. Searched for more pics and yes, they appear to be the same.
Title: Re: Optical cable from Brymen BM869 to Sanwa PC7000?
Post by: Kaziq on October 22, 2017, 08:27:57 am
I just found this topic: https://www.eevblog.com/forum/testgear/brymen-ir-connection-protocol-anyone-sniffed-it-yet/25/ (https://www.eevblog.com/forum/testgear/brymen-ir-connection-protocol-anyone-sniffed-it-yet/25/)

...and I managed to communicate with PC7000 (with a uP and two IR leds) using the same protocol that others use for BM869.

So if anyone else wants to know: yes, it works! :)
The LCD segment mapping seems to be identical too.