Xylem iRIS 150 GPRS DATALOGGERS - Manual (Page 33)

27 – IRIS 150 V1.11 User Guide
iQuest (NZ) Ltd - PO Box 15169, Hamilton, New Zealand Tel: +64 7 857-0810 Fax: +64 7 857-0811 Email: [email protected] 27
6.3 Scan Mode / Scan Rate
To optimise the battery consumption when operating from the internal battery, the iRIS has a configurable
“scan” option that is changed via Option 2 in the Main Menu See Section 5.3.1. The scan option has four
modes:
6.3.1 Continuous Mode
In this mode, the iRIS will process its program continuously. This mode must be used if the logger is
attached to instruments that require rapid and continuous measurements such as wind monitoring or special
serial devices.
6.3.2 Event Mode
In this mode, the iRIS will process its internal program only on an event, either a digital input activation
and/or when a timed event log is due to be stored. This is the lowest power mode and is intended for
applications where the logger is powered from only its internal battery. Typical installations are rain gauges
and pulse type flow meters. Pulses on the digital input(s) are captured and processed on an event basis. If a
sensor is set to timed event mode, pulses are accumulated and stored at the predetermined time - otherwise
they are logged immediately.
6.3.3 Timed Mode
In this mode, the iRIS will only scan its program once at the programmed rate. This is a lower power mode
than continuous and will typically be used for low power analogue measurements. A typical installation is a
river level site. Pulses on the digital input(s) are captured and processed on an event basis. If a sensor is
set to timed event mode, the pulses are accumulated and stored at the predetermined time.
Note: The log rate for each enabled sensor must be the same as, or an exact multiple of the scan
rate. For example, if the iRIS has two analogue sensors attached, one configured to log every 5
minutes and the other every 15 minutes; the scan rate should be set to 1 or 5 minutes. If however,
the scan rate was incorrectly set, say to 15 minutes, two out of every three logs of the five-minute
sensor would be missed. If it was set, say to 2 minutes, logging would only occur at multiples of two
minutes, so both sensors would fail to log certain samples, with times such as xx:05, xx:15, xx:25
and so on missed.
6.3.4 Telemetered Mode
This mode is identical to continuous mode, except that the RS232 port is maintained in a permanently on
state. Even though the logger mode may be set to “Telemetered”, whether or not it is actually “active” is
dependent on certain criteria.
Telemetry mode is active when no user is logged in and there has not been a key pressed or terminal action
for at least 60 seconds (i.e. deemed that no one is on site). It is also active when a user is logged in as the
enabled a communication call-back test to be initiated. It is inactive when a key has been pressed and
terminal activity is occurring. To enable terminal use, the user will need to log out. See Section 6.2.4.1.
6.4 General Hints
If the iRIS will not to be used for some time, remove the internal lithium battery.
Always check the time and date when commissioning the unit. The clock will be invalid if the internal
battery has been removed at any time.
Initializing the unit after installation and calibration has been completed is strongly recommended to
avoid unwanted and/or invalid samples being logged. See Option 1 in the Miscellaneous Menu (Section
5.3.1)