Data Logger Functions; Internal Data Memory - Ahlborn ALMEMO 2470-1S Operating Instruction

11. Functions
If any measured value overshoots or under-
shoots its associated limit values, the associ-
ated channel is selected automatically, the
measured value is displayed on an illuminated
red background, and an acoustic alarm is out-
put. Whether the limit value in question is an
overshot MAX or undershot MIN is indicated by
the direction of the flashing arrow ▲ or ▼. The
acoustic alarm lasts 10 seconds; the red back-
ground can be switched off by pressing any
key. The measured value then appears with a
flashing arrow either in red (if MAX overshot)
or blue (if MIN undershot). The function field
shows the high / low peak value in the appro-
priate color. (see 10.3) Here, by again pressing
the or key, the associated limit
MAX MIN
value can also be displayed with symbol MAX
LIM or MIN LIM. The alarm signal can also be forwarded via various relay cables
or used to trigger certain actions. (see Manual, 6.3.9) This alarm status remains ef-
fective until the measured value returns to within the prescribed limit value by the
amount set as hysteresis.

11.2 Data logger functions

The ALMEMO 2470-1S and 2470-2S are data loggers with an internal EEP-
®
ROM. On the 2470-2S it is also possible to add a memory connector with a
memory card. To control measured value recording 4 additional functions are
provided.
Memory capacity display ´FrEE´ (see 11.2.3) Cycle ´ZY´ (see 11.2.4)
Date ´DA´ and time-of-day ´ZT´ (see 11.2.5)
For the basic principles of saving data in ALMEMO devices please see the de-
®
scription in the Manual, Section 6.9.

11.2.1 Internal data memory

The internal 512 KB EEPROM data memory is sufficient for up to 100 000
measured values (depending on the number of channels). In the event of a
failure in the supply voltage the measured data is retained intact. The available
memory capacity ´FrEE´ is displayed in ´KB´. The EEPROM can be recon-
figured from ring memory to linear memory. (see Manual, 6.10.13.2)
PLEASE NOTE ! The first time the device is started only one sensor configur-
ation is saved to the internal memory; however, with effect from the next start
this can be supplemented by additional sensors. If, whenever the device is
subsequently started, a different sensor is found to be connected, the display
shows ´Er.MEM´. It is now still possible, by pressing ´ESC´, to cancel and read
out the old measuring operation. If, however, this error message is acknow-
32 ALMEMO 2470