ST-72 User's Manual
Document: UM-1007
Revision Level A
35
2.4.6.1 INFO / MEASUREMENT NAME
The first two items in this menu are for entering the 16 character
Measurement Name
and 6 character
engineering unit
ASCII fields. Eunits should define the units of measure
for what this channel is to display.
Measurement Name
should describe the source of
this data in the user’s terminology.
of this manual describes how to use the
front keypad to modify these fields.
2.4.6.2 ZERO / SPAN
The
ZERO / SPAN
entries allow configuration of the measurement range displayed by
this channel. Measurement Range works along with
A/D Counts
menus, described in
, to define the range of the input signal’s engineering units. For example,
if a channel’s input is 4-20mA from a transmitter monitoring 0 to 10ppm chlorine, then
the
Zero
value should equal 0.000 and the
Span
value equal 10.00. The six ASCII
engineering units previously entered are automatically displayed at the top of each
menu as a reminder. Four digits must appear in this entry so trailing 0’s may appear
here that are not displayed on other data screens.
2.4.6.3 DECIMAL POINTS
Resolution of displayed channel values is configured in this menu by setting the number
digits trailing the decimal point. Values are limited to a maximum of four digits, and a
polarity sign. An auto-ranging feature displays the highest resolution allowed by this
menu’s decimal point entry. For example, if three decimal points are entered, and the
range is 0 to 100ppm, the reading will be
0.000
at 0ppm and
100.0
at 100ppm.
However, this may be undesirable due to the high resolution at zero unless the sensor’s
output is extremely stable. If decimal points are limited to one, the 0ppm reading
becomes
0.0
and the 100ppm reading remains
100.0
. Resolution may be limited further
by setting decimal points to 0. In the above example, this would cause 0ppm to display
0
and 100ppm to display
100
.
2.4.6.4 CHANNEL ON?
The
Channel On?
entry determines if this channel is to be utilized. Turning it off will
cause the controller to never process inputs applied to this channel and no alarms will
be tripped or data displayed. Inactive channels will be grayed out on the Main Data
screen and skipped when scrolling through the 30 Minute Trend screens. Channels may
be turned off in groups of 16. This is done in the System Setup menu described in
2.4.6.5 ZONE
The
ZONE
feature allows assigning of channels into up to eight possible
ZONES.
This
is useful for applications that may need all of alike gases or inputs from a certain area to
Summary of Contents for ST-72
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Page 108: ...ST 72 User s Manual Document UM 1007 Revision Level A 102 Figure 6 4...
Page 128: ...ST 72 User s Manual Document UM 1007 Revision Level A 122 8 5 3 COPY CHANNELS Figure 8 7...
Page 129: ...ST 72 User s Manual Document UM 1007 Revision Level A 123 8 5 4 PROGRAMMABLE RELAYS Figure 8 8...
