Setting The Recorder Output Span - Hach CL17 Instrument Manual

Section 2

2.7.3 Setting the Recorder Output Span

Page 38
Instrument Menu Structure
Perform the procedure below to assign functions to AL1 or AL2:
1. Press the key.
MENU
ALARMS
2. Press to select
ENTER
and either the alarm set point (HI or LO), SA (System Alarm), or SW
(System Warning).
3. To change the AL1 (or AL2) assignment, press
be changed will flash. The arrow icons indicate active arrow keys. Press
the or
UP DOWN ARROW
Press the
RIGHT ARROW
4. Press to select the displayed assignment.
ENTER
5. Repeat the procedure to customize the other alarm relay.
In addition, a selection to recall or clear warnings is available. Access as
follows:
1. Press the key.
MENU
ALARMS
2. Press to select
ENTER
AL2) along with the alarm set point (HI or LO), SA (System Alarm), or SW
(System Warning).
3. Press the
DOWN ARROW
4. When the appropriate option is displayed, press ENTER.
• RECALL WARNINGS—Momentarily shows all active warnings then
displays .
DONE
• CLEAR WARNINGS—Clears all resolved warnings then momentarily
displays .
OK
5. Press twice when done.
EXIT
This menu allows the Recorder Output High and Low limits to be set and also
offers the capability to use the ON SYSTEM ALARM option to communicate
an alarm condition. Use ON SYSTEM ALARM to send a signal to the control
room using the recorder output, to drive any device being controlled to full off,
or to maintain the present level if the analyzer goes into System Alarm status
and shuts off.
The CL17 is supplied with the recorder output set at maximum range. At
maximum range, a chlorine concentration of 0 mg/L provides an output of
4 mA and a concentration of 5 mg/L gives an output of 20 mA. The output
span can be adjusted to bracket any portion of the 0–5 mg/L range with the
4–20mA signal. For instance, this function can be used to bracket a lower
range for increased recorder resolution.
For example: if chlorine concentration of your sample is normally 0.5–0.7
mg/L, the recorder output span can be set for 0–1 mg/L (where 4 mA equals 0
mg/L and 20 mA equals 1 mg/L).
will be displayed.
. The screen will display AL1 (or AL2),
ALARMS
ENTER
key to scroll through the available assignments.
key to change the value of the high or low alarm.
will be displayed.
. The resulting screen will display AL1 (or
ALARMS
key to scroll through the options.
again. The item to
54400_start.fm