Getting To The Points - Omega RD8800 User Manual

Chapter 3 Getting Started

3.2 Getting to the Points

The Instrument is a 15 point Recorder of which up to twelve channels may be direct or real world inputs. These are
typically voltages or currents. Any channel not being used to record or display live inputs may be used as a
computational channel. Inputs can be conditioned or scaled to display any range of engineering units. Refer to
Figure 3-10 below.
Figure 3-10 Data Flow
There are four distinct levels of data handling, namely conversion, conditioning, scaling and display/record. Conversion
applies only to live inputs and is the process of converting real world analog signals into a 16-bit digital value that
can be used by the Recorder. There are five full-scale ranges for all conversions 150 mV, 1.25 V, 2.5 V, 12.5 V and
25 V DC. The converted values pass to a conditioning block which converts the binary value, which is effectively a
percentage of full scale, into a value useful to the user. Conditioning includes converting the binary value into a
representative voltage, conditioning and linearizing this voltage to represent for example, a real world temperature
as might be input by a thermocouple or RTD, and applying any other computation as required. The conditioning
block handles 15 channels. The outputs from the conditioning block are referred to as base points and may be fed
back to the inputs of the conditioning block to form the basis (base point) for other base point computations. This
includes tracking peak or valley values, doing moving averages, timed averages, difference, totalization or any other
user-entered equation.
The input to any channel in the conditioning block can be any one of the base points, or it can be the live inputs.
Live inputs can have input and output scaling applied in the conditioning block unless this is predefined by the
nature of the input (i.e. thermocouples). An example of input/output scaling is given in section 3.3.
Page 3-7
Artisan Scientific - Quality Instrumentation ... Guaranteed | (888) 88-SOURCE | www.artisan-scientific.com