Universal transmitter 8390-1
4. CONNECTING THE TRANSDUCERS
Virtually any ALMEMO
®
sensor can be connected to the ALMEMO
®
input socket M0
(1). To connect your own existing sensors you simply need the appropriate ALMEMO
®
connector.
4.1 Transducers
The ALMEMO
®
Manual includes detailed descriptions of the comprehensive ALME-
MO
®
sensor range (see Manual, Chapter 3) and of how to connect your own existing
sensors to ALMEMO
®
instruments (see Manual, Chapter 4). All standard sensors with
an ALMEMO
®
connector usually have the measuring range and units already program-
med and can thus be connected to any input socket without further adjustment. A me-
chanical coding system ensures that sensors and output modules can only be con-
nected to the correct sockets. Each ALMEMO
®
connector also incorporates two snap-
lock levers; these snap into position as soon as the connector is inserted into the so-
cket, thus preventing unintended disconnection if the cable is accidentally pulled. To
withdraw the connector, both these levers must be pressed in at the sides.
4.2 Measuring inputs and additional channels
Measuring instrument ALMEMO
®
8390-1 incorporates an input socket M0 (1), to which
initially measuring channel M0 is assigned. ALMEMO
®
sensors can, however, if ne-
cessary, provide four channels. Additional channels are available primarily for
humidity sensors (temperature / humidity / dew point / mixture ratio) or
flow probes and chemical probes incorporating a temperature sensor. A single sensor
can be programmed, if necessary, with several ranges or scaling processes; similarly,
if pin assignment permits, two sensors can be combined on one connector (e.g. rH /
Ntc, mV / V, mA / V, etc.).
Measuring point numbering
Each additional measuring channel in a connector lies one level higher. In this new se-
ries the levels are now numbered in standard decimal form, i.e. the front digit indicates
the level. In this way the measuring point number (and thus also the programmed re-
ference channels) for all devices with 1, 2, 5, or 10 inputs always remains the same. If
reference channels are programmed that are not available in the device, the default re-
ference channel (the 1st in the connector) is used.
On the measuring instrument this gives the following channel assignment :
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