Help me decide MSO Scope or Scope + LA

[Turby]

Hi all, first post so be kind!

Over the last few years I have been using a 2 channel Tektronix TDS210 oscilloscope and an old IkaLogic 4 channel logic analyser. Previously I have used these on hobby projects on average say once a month. Recently I had a hobby project which required scoping 4 channels simultaneously so that was out the question.

I now have a work project which will last around 6 month which requires a scope with 4 channels as well as up to 8 logic / digital channels. Its all microcontroller based signals, no faster than 50 MHz SPI, low speed I2C, RS232 & RS485, a later phase will also include CAN 2.0B Bus so ideally will need decoder for that. Budget is around £800 GBP but could stretch if there is a big advantage in doing so. I do like having a sperate scope as it frees up valuable screen real estate, but I would like to be able to do screen dumps, capture traces etc via USB if that's at all possible. The ability to generate low frequency (sub MHz) square wave would also be a nice bonus as well.

I've read lots of reviews on various scopes and was wondering whether to go for separate oscilloscope (eg Rigol DS1054Z) and logic analyser (eg Saleae 8 / 8 Pro) or go for a combined MSO. There's a chance of a RS PRO 2104EA 16 channel mixed oscilloscope for £800 which I believe is a rebadged GW INSTEK MSO-2104EA. I can see synchronising analogue and digital signals as a major benefit of a combined MSO as being very useful/necessity.

Any useful advice / suggestions ? I'm based in the UK as well if anyone knows of any deals. Open to having good condition pre-owned as well.

[madires]

A separate LA has the benefit of a huge memory depth (your PC) and also comes with a much better user interface (your PC again). However, you should know what you need or what suits you best, and decide based on that.

[Fungus]

Combined MSOs are usually a bad deal.

I can see synchronising analogue and digital signals as a major benefit of a combined MSO as being very useful/necessity.

Correct, and Saleae have a basic analog capability for this purpose.

[nctnico]

Combined MSOs are usually a bad deal.

No. Not at all. You can do 90% of the tasks of a logic analyser with an MSO. Also an MSO can show digital signals in realtime.

If I had to choose between an MSO or logic analyser then I'd choose the MSO. However a good logic analyser is a good add-on to have but don't expect to use it often. I have not powered my logic analyser on for over a year. Maybe even 2 years.

[2N3055]

What is more important to you:

1. decoding really long sequences of serial protocols to drug software code
or
2. time correlating  digital and analog signals, and decoding in that context.

If 1. than you need a streaming protocol analyser.
If 2. than you need MSO.

Or, 3. what I would do, is go with MSO (because when you need it, it cannot be improvised)  and get one of those 20 USD logic analysers and use it with Sigrok for software debug, or splurge for 150 USd DSLogic for a serious device.

If you got a good price for that GW instek (good price being less than 1200€ new) grab it... That is a good scope.
If it is more than that, you can take a look at Rigol MSO5000 or Siglent 2104X+. Siglent is a bit more expensive, but better. Both are more modern devices with touch screen. Rigol is good for digital debug and has 2 ch siggen, siglent only one. Siglent is better for analog(better, low noise front end), while still good for digital. Siglent supports CAN FD. So mixed bag.. You need to compare what is more important to you.
Dealers choice.

My 2c.