Hach-Lange SD900 Refrigerated Sampler, SD900 AWRS User Manual - Manual (Page 34)

Operate from an external signal (setpoint sample)
The setpoint sample option starts and stops the sampler after a signal is received from an external
device such as a flow meter. The current program status shows when the sample program is
inhibited by an external device.
Note: Setpoint and stormwater sampling cannot be enabled at the same time.
1. Select PROGRAM SETUP>MODIFY SELECTED>ADV SAMPLING from the main menu.
2. Select SETPT SAMPLE>SETPT TRIGGER>EXT TRIGGER >ENABLE.
3. Select SETPT SAMPLE>SETPT CONTROL and select one of the setpoint options:
Option Description
START ON SETPT The sampling program operates until the program is complete.
START/STOP The sampling program operates until the external signal is no longer received.
4. To use a setpoint delay, enter a delay time in hours and/or minutes. The delay time starts when
the external signal is received. The program starts when the delay time expires.
Use an SDI-12 device for setpoint sampling
When an SDI-12 device is connected to the controller, the measurements can be used as setpoint
sampling triggers (in addition to the external inhibit). A maximum of one measurement trigger can be
enabled that is independent of the external trigger. If multiple triggers are enabled, the program starts
from at least one trigger and stops when all triggers are cleared.
Each trigger can be defined as a high or low setpoint. Additionally, an optional deadband value can
be set. A deadband prevents the trigger from rapidly changing between active and inactive states
when the measurement value is near the setpoint. Refer to
Figure 14 .
1. Go to PROGRAM SETUP>MODIFY SELECTED>ADV SAMPLING>SETPT SAMPLE>SETPT
TRIGGER.
2. Select a measurement channel.
Note: A check mark is shown when a channel is enabled as a trigger.
3. Enter a setpoint trigger within the range that is shown.
4. Enter an optional deadband value.
5. Select ENABLE.
6. Select SETPT CONTROL to define how the sample program will operate.
Option Description
START ON SETPT The sampling program operates until the program is complete.
START/STOP The sampling program operates until the trigger is cleared.
7. To use a setpoint delay, enter a delay time in hours and/or minutes. The delay time starts when
the setpoint trigger becomes active. The program starts when the delay time expires.
Note: Setpoint control and delay options are global settings that are applied to all triggers.
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