Ahlborn ALMEMO 710 - 7.4 Sensor supply; 7.5 Switching ON; OFF, reinitialization; 7.6 Data buffering

7. Power supply
ever, the power supply has to be electrically isolated from the transducers or if
a larger input voltage range (10 to 30 V) is required, then electrically isolated
supply cable ZA 2690-UK2 (12V, 1A) must be used. It will then be possible to
use the device in a 12-volt or 24-volt on-board supply system; however, the
battery will slowly be recharged.
7.4 Sensor supply
At the terminals + (plus) and - (minus) in the ALMEMO
®
plug there is a config-
urable sensor supply voltage available (self-healing fuse, 500 mA). This volt-
age is derived automatically from the minimum sensor supply voltage for all
sensors; however, this can be replaced as and when required with a higher
voltage. It can be programmed in the menu ´Settings > Power supply > Sen-
sor voltage setpoint´. (see 13.8)
In mains operating mode the sensor voltage is set automatically to 12 V. Other
voltages (12 / 15 / 24 V or references for a potentiometer and strain gauge)
can also be obtained using special plugs. (see Manual 4.2.5/6).
7.5 Switching ON / OFF, reinitialization
To switch the device ON / OFF press and hold down the touchkey ON-OFF (6).
The measuring menu most recently selected always appears in the display
first.
After the device is switched off the real-time clock continues to run and all
saved values and settings are retained intact. (see XREF)
If interference (e.g. electrostatic) or a malfunction (e.g. battery failure) causes
the device to behave abnormally, it can, by means of a slide switch located un-
der the rubberized cover Ax (4) on the rear of the device, be switched off and
then back on again. A reset is performed as follows : shortly after switching on
with the slide switch, also press the
HOME
key. This will have the effect of
deleting all device programming and user menus; only the time-of-day, mem-
ory, device designation, device adjustment, and sensor programming in the
ALMEMO
®
plugs remain intact.
7.6 Data buffering
The sensor's programming is stored in the EEPROM in the sensor plug; the
device's calibration and programmed parameters are stored in the EEPROM
on the device itself; and all recorded measured values are stored in the de-
vice's integrated flash memory - all on a failsafe basis. Date and time-of-day
are buffered by a dedicated lithium battery; this data is retained intact for years
- even if the device is kept switched off and the batteries are empty.
18 ALMEMO
®
710