Analog Channels; Computed Channels; Channel Numbering; Mx+B Scaling - Fluke NetDAQ 2640A User Manual

Analog Channels

The analog channel (1 to 20) measurement connections are made via the
Universal Input Module. External signal conditioning for the analog inputs is not
necessary. The host computer configures all analog channels using NetDAQ
Logger.

Computed Channels

In addition to the 20 analog channels, the instrument provides an additional 10
computed channels (21 to 30) by processing analog channels and other computed
channels. The following methods are used:
The average of a group of channels,
The difference between any two channels,
The difference between a channel and the average of a group of channels,
A mathematical equation.

Channel Numbering

Each instrument channel, measured or computed, is identified by Global Channel
Number (GCN). The first two digits of the GCN are the Base Channel Number
(01 to 99) that identifies the instrument. The last two digits are the channel
number. For example, GCN 2618 indicates instrument 26 and analog channel 18
(below). When the instrument is in the quiescent state, the channel number of the
GCN shows dashes, for example, 45-- for instrument 45.

Mx+B Scaling

Mx+B scaling multiplies a measurement by a multiplier M and then offsets it by
an offset B. For example, Mx+B scaling of 100x+50 applied to a measured or
computed channel value of 1.15 results in a reading of 100(1.15)+50=165. A
common use of Mx+B scaling is to calibrate a sensor or transducer to provide for
display and recording in engineering units. The Mx+B annunciator lights when a
monitored channel has scaling applied.
Instrument Features and Capabilities
SCAN
Mx+B ALARM
MON
Overview
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