Data buffering
7.7 Data buffering
The sensor's programming is stored in the EEPROM on the sensor plug; the
device's calibration and programmed parameters are stored in the EEPROM
on the device itself; both are fail-safe. Date and time-of-day settings are re-
tained intact if the device is just switched off but will be lost as and when the
batteries are replaced.
8. CONNECTING SENSORS / TRANSDUCERS
Virtually any ALMEMO
®
sensor can be connected to input sockets M0 / M1 (1)
on ALMEMO
®
measuring instrument 2470-2/2S. To connect your own existing
sensors you simply need the appropriate ALMEMO
®
plug.
8.1 Sensors / transducers
The ALMEMO
®
Manual includes detailed descriptions of the comprehensive
ALMEMO
®
range of sensors (
see Manual, Chapter 3
) and instructions for connect-
ing your own existing sensors to ALMEMO
®
instruments (see Manual, Chapter
4). All standard sensors with an ALMEMO
®
plug usually have the measuring
range and units already programmed and can thus be connected to any input
socket without further adjustment. A mechanical coding system ensures that
sensors and output modules can only be connected to the correct sockets. All
ALMEMO
®
plugs incorporate two snap-lock levers; these snap into position as
soon as the plug is inserted into the socket, thus preventing unintended discon-
nection if the cable is accidentally pulled. To withdraw the plug both these
levers must first be pressed in at the sides.
For the ALMEMO
®
2470 series with the optional seal (OA 2479-IP) new spe-
cially designed sensors are available with spray-coated ALMEMO
®
plugs incor-
porating a double sealing lip to protect the socket unit against the effects of
splashing water. For any unused sockets protective stoppers are available.
8.2 Measuring inputs and additional channels
ALMEMO
®
measuring instruments 2470-1/2 have respectively 1 and 2 input
sockets (1); to these input sockets initially measuring channels M0 (and M1)
are assigned. However, ALMEMO
®
sensors can, if necessary, provide up to 4
channels. The additional channels can be used in particular for humidity
sensors with 4 measurable variables (temperature / humidity / dew point / mix-
ture ratio) or for function channels. Each sensor can if necessary be pro-
grammed with several measuring ranges or scaling settings;
2 or 3 sensors, if pin assignment so permits, can be combined in a single plug
(e.g. RH / NTC, mV / V, mA / V, etc.). The additional measuring channel num-
bers per plug go up in steps of 10 (e.g. the first sensor has channels M0, M10,
M20, M30, the second sensor has channels M1, M11, M21, M31 etc.).
Device-internal channels:
The 2470-1SRH and 2470-2/2S incorporate 4 additional channels M4, M14,
ALMEMO
®
2470
17