Corvus : What is a Measurement Process?

When acquiring data in a measurement task that requires multi channel data to be collected in a manner suited to different measurement types .

Let's say you are faced with a measurement task where some channels measure vibration on a fixed frequency range at a sample rate of 2kHz and others are measuring temperature say every 10 seconds. If all your channels are locked together  using the same the data acquisition set up, you must choose the vibration set up for all channels. This is just fine for the vibration analysis, but you are taking a way too much data for your temperature channels.

The solution is to set your Corvus system up with two processes one sampling at 2kHz and the one shot every 10 seconds. You just allocate the relevant channels to their measurement process. The measurement system needs to be able to synchronise all processes so that the data can be displayed live or recorded and played back with all channel data with the correct timing.

There are two levels of Corvus:

Single process

A single process running in a single chassis with up to 268 channels.

Two processes

Two processes running in a single chassis with up to 268 channels.

Two processes

Two processes running in three chassis with up to 1024 channels.

Four processes

Four processes running in three chassis with up to 1024 channels.

Six processes

Six processes running in three chassis with up to 1024 channels.

 

A typical large test bed system running Corvus with 6 processes is shown below

Process	Order Tracking	Vibration	Vibration 2	Acoustics	Pulsation	Static Process
Number off input channels	48	64	48	32	64	32
Bandwith/Channel	Tracking	1 kHz	5 kHz	20 kHz	10 kHz	1
Sample rate/Channel	64 x RPM	2.56 kS/s	12.8 kS/s	51.2 kS/s	25.6 kS/s	1 S/s
Blocklength/Channel	256	2048	1024	4096	2048	1
Trigger	External	External	External	Free Run	Free Run	Free Run