Table of Contents
Advertisement
HA71 Digital Gas Controller
2.2.10 Input Measurement Range
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
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 10 ppm
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.
2.2.11 Decimal Point Resolution
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 100 ppm, the reading will be 0.000 at 0 ppm and 100.0 at 100
ppm. 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 0 ppm reading becomes 0.0 and the 100 ppm
reading remains 100.0. Resolution may be limited further by setting
decimal points to 0. In this example, this would cause 0 ppm to display
0 and 100 ppm to display 100.
2.2.12 Turning off Unused Channels
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 have a line drawn through them on the Setup screen as
indicated by channels 15 & 16 in
HA71 Technical Manual
Section
2.2.5, to define
Figure
2-1. If less than 9 channels are
to be activated, the HA71 may be set for 8 channel mode, deactivating
channels 9-16. This is done in the System Setup menu described in
Section
2.3. The HA71 will only allow 15 channels to be turned off;
at least one channel must remain on.
2.2.13 Copy Data To?
This menu simplifies the Setup procedure by allowing similar channels
to be copied from one to another. For example, if all channels are
identical except for the Measurement Name entry, channel 1 could be
configured and copied to channels 2 – 16. Only Measurement Name
then must be configured on channels 2 – 16. Use EDIT to increment
channel numbers and UP/DN to point to Copy Now? Press EDIT
once more to copy.
2.2.14 CAL Mode
CAutIoN
Each channel's CALIBRATION menu is inactive unless its Input Data
From: menu, described in
Cal or Sensor Direct. HA71 CAL MODE features allows pushbutton
calibration of zero and span values. This feature should be utilized
only when there are no other zero/span controls within the monitoring
system since it is inappropriate to calibrate a signal at more than one
point. Therefore, if calibration is to be performed at another transmitter
or monitoring device, the HA71 CAL MODE feature should not be used.
The CALIBRATION MENU allows entering the correct Cal ZERO &
Cal SPAN setpoint values needed to calibrate the sensor. These are
entered in the same engineering units as input range. Set Zero & Set
Span controls in this menu allow pushbutton calibration by moving
the pointer to each and pressing the EDIT key. A live reading of the
channel's value allows calibration checks to see if an adjustment is
needed. Unintentional calibrations are reset by the Unity Gain menu
2-7
Section
2.2.4, is set for Analog with Local
Revision 3 (04/08)
Advertisement
Table of Contents
