Omega Engineering OMB-CHARTSCAN 1400, User Manual

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ChartScan User’s Manual ChartView Software Reference 4-35
Channel Configuration Columns
1)
Channel (CH)

This column serves only as a channel number indicator. The channel number cannot be
changed from this column.
2)
On 
The On column allows you to enable a channel for data collection. When a cell or block of cells in
this column is selected, a selection box will appear that allows “On” to enable or “Off” to disable the
channel. Double-clicking a cell in this column toggles the channel’s enable status. Clicking the
Make All
Channels Active button enables (turns all channels “on”). Clicking on the Make All Channels Inactive
button disables all channels (turns them “off”), with the exception that channels assigned to charts can only
be turned off from the display configuration setup.
3)
Readings

The reading column displays the scanning device input readings. The column is activated
when you select the Enable SpreadSheet Reading button. The column’s values are real-time channel values
from the instrument and cannot be altered by the user. This column will update the readings as fast as the
computer will allow.
Note: Other areas of the SpreadSheet cannot be altered while the channel Readings column is enabled.
4)
Type

A block of cells in this column can be selected for convenience of single type selection.
Double-clicking a cell will select the next available type.
5)
Label

The Label column identifies the input channel by descriptive name. The label is used when
selecting a channel in the trigger and chart selection lists. The label column automatically uses the channel
number as a default. You can change the label to any alpha-numeric designation not exceeding eight
characters. Each label used must be unique (specific) to its designated channel.
6)
Units 
Cells in the Units column are dependent on the Type selected and automatically change when the
type is changed, for example temperature units will be replaced by volts units when changing from a
thermocouple type to a volts type.
If the channel is configured for Temperature, the units automatically change to
°
C (default); at this point,
you have the option of selecting a different engineering temperature unit (
°
F,
°
K,
°
and R). Note that the
mX+b equation, discussed in the following text, is typically not used for temperature readings, since
temperature data will be linear. However, you can use the equation in temperature applications, for
example: setting b to -32 in order to watch deviations from freezing point when temperature is in °F.
In addition, with ChartView Plus you can subtract a reference channel from the mX+b equation to obtain a
temperature differential, as indicated in the following example.
Example:
A heated room has 2 thermocouples (T1 for CH1 and T2 for CH2); with T1 being in the center of the room
and T2 positioned at an outer wall. If the outer wall is monitored to ensure a temperature within ±2°F (of
the temperature indicated by thermocouple T1), then CH1 can be used as a reference channel such that its
value will be subtracted from the actual value for channel 2. Assume the central thermocouple is reading
90.5°F and the outer thermocouple (for CH2) is reading 89.0°F. In this case, we can use the equation so
channel 2’s charted reading will not be of the actual temperature, but will be the differential between CH1
and CH2, e.g.:
y = (mX + b) - ref. chan
; where:
y = Channel 2’s charted value (a temperature
differential)
m = 1
b = 0
X = CH2
ref. Chan. = CH1
Channel 2’s charted value = (1 x CH2 + 0) - CH1
Channel 2’s charted value = (1 x 89.0°F + 0) - 90.5°F
Channel 2’s charted value = -1.5°F
Note: The reference channel feature is only available with ChartView Plus .