32 digital channels on scope

[treez]

Hello,

We are expanding our engineering operations and need new kit.

We are currently using an Agilent MSO6034A scope which we need for the 16 digital channels.....

http://www.home.agilent.com/agilent...ckey=564674&nid=-35165.536905500.00&id=564674

However, we would prefer to have 32 digitall channels.

Does any reader know of such a scope with 32 digital channels? If it exists, it is hard to track down.

Also, i was going to re-order some more of our TDS range Tektronix scopes but was stunned to find that these have non-isolated channels.....it is the TPS range that have isolated channels. I thought all multi-channel scopes these days had isolated channels.

 

[geekEE]

I don't know of a scope with digital channels, but there are certainly Agilent logic analyzers that have analog channels (or have them available as modules). If you're using it mainly as a scope, it's not as convenient, but when you need the large amount of digital channels, the triggering is much more sophisticated than the Agilent MSO's.

Glenn

 

[MacGyverS2000]

Check on connectivity between two units. A few years back we needed both high-speed analog and a number of digital channels... the solution was to connect two units (Agilent, if memory serves) with one acting as a slave. We could get 128 digitals and 4 analogs.

Dan - Owner

http://www.Hi-TecDesigns.com

 

[geekEE]

That's a very good point Dan. The Agilent MSO series has an ext trigger out on the back and an ext trigger in on the front panel.

Glenn

 

[VEBill]

I can't provide a specific reference, but don't some of the 'scope on a card' boards that you install into a PC have very high input channel counts?

 

[btrueblood]

"I can't provide a specific reference, but don't some of the 'scope on a card' boards that you install into a PC have very high input channel counts?"

Yes, or they can, using the same master/slave setups as mac was talking about with scopes. National Instruments

http://www.nationalinstruments.com,

and Measurement Computing

http://www.measurementcomputing.com,

are just two that I know of that sell boards with this capability. As far as isolation, most boards and as the OP noted, a lot of newer scopes are wanting you to buy seperate isolation modules, typically sold on a channel-by-channel ba$i$.

 

[melone]

What sampling rate do you need for this Portable LA?

 

[geekEE]

btrueblood, based on your comments, I assume these isolation modules are expensive. Do you happen to know how their price compares to a differential probe? There are a few times when I've wanted a diff probe at work, but haven't gotten around to getting one.

Glenn

 

[MacGyverS2000]

A good diff probe is easily $1k... makes a scope lead made from some audio cable and a Radio Shack clip look positively beautiful if you're the one payin' the bills.

Dan - Owner

http://www.Hi-TecDesigns.com

 

[btrueblood]

http://www.measurementcomputing.com...alog&mscssid=FBUA8HDQ01GC8GBVFHLK2RDL70PBCEDB

Sorry about that, it's a long link. Search for ISO-5B modules on

http://www.measurementcomputing.com

if the above doesn't work, or follow the links for "external signal conditioning".

Short answer is $150-$200 per channel depending on how much amplification the module is doing. Note that these things typically only go to +/-40 vdc ratings (relative to the board ground), past that you need to look at other methods or suppliers. Be careful with these, I don't think they will behave with anywhere near the low capacitance of fancy scope probes, and also affect the frequency response of the signal (400 Hz is a rating on one of them...). Dunno how fast you need to go. National used to offer similar devices, with better ranges and faster response, for more money...but I can't find the isolation products on their site.

 

[geekEE]

Ah, the 5B modules are what you were talking about. I misunderstood. I thought you knew about some isolation module that went between a scope and a scope probe. Well, that frequency response is way below what I would need. I guess I've got to see if I can talk folks here into spending the cash on a diff probe. That will take some wrestling.

Glenn

 

[Madcow]

Lecroy offers an option for 32 digital inputs.

http://www.lecroy.com/tm/Solutions/MixedSignal/MS-32/default.asp

Agilent and Tektronics allow some of their scopes and logic analyzers to be connected together and function as one.