Halytech
hydroSpider2 User’s Manual v1.23
Page 62
In that example, the pump (and therefore the control) should operate whenever the water level is
too low, whether or not the alarm has been acknowledged. There is no need to limit how often the
pump should run, and no need to wait for human intervention – the control action should be fully
automatic.
However, in some situations it is important that a control action occur only once or no more than
every so often.
Consider the situation where the control is wired to trigger a sampler. After an alarm (perhaps based
on a temperature or salinity reading) triggers the control action, starting the sampling operation, no
more samples can be taken until the sample has been removed. In that situation, the “Once until
alarm acknowledged and reactivated” option should be selected to inhibit further control actions
(samples) until this alarm has been acknowledged.
Or, perhaps a pump is to be operated for five minutes whenever an alarm is activated – but should
not operate more than once per hour. In that case, the pump would be connected to a control, and
the control action would be to pulse on for 300 seconds. To ensure that the pump only operates
once per hour, the “Once until alarm acknowledged and reactivated” option should be selected, and
the auto acknowledge time can be set to 60 minutes. When the alarm is triggered, the pump will
operate for 5 minutes (300 seconds), but will not turn on again for 60 minutes, when the alarm is
automatically acknowledged.
5.10.8
Advanced - Fast logging
When the fast logging option is enabled, any input channels with their logging period set to
“General” will begin logging at the rate specified by “General fast logging period” on the
Change
Input Setup
page when the alarm is triggered.
This is useful in many situations, including:
If data is only required for a few hours a day. This can be achieved by configuring an alarm
with the fast logging option in conjunction with a Time/Date trigger source (so that it goes
active at the specified times).
If faster rate data is required when an input is active. For example: normally logging water
level data every 30 minutes until the level rises above a certain point, and then logging
water level every 1 minute until the level falls again.
Conditional fast logging becomes even more important when the sensors are being powered from a
battery source, since logging only when required can dramatically improve the system’s battery life.
