Connecting The Transducers; Transducers; Measuring Inputs And Additional Channels - Ahlborn ALMEMO 5690-2M Operating Instructions Manual

8. Connecting the transducers

8. CONNECTING THE TRANSDUCERS
Virtually any ALMEMO
®
ALMEMO modules types (6) and (7). To connect your own existing sensors
you simply need the appropriate ALMEMO
are described below.

8.1 Transducers

®
The ALMEMO
®
ALMEMO range of sensors (see Manual Ch 3) and instructions for connecting
your own existing sensors to ALMEMO
standard sensors with an ALMEMO
range and units already programmed and can thus be connected to any input
socket without further adjustment. A mechanical coding system ensures that
sensor and output modules can only be connected to the correct sockets. All
®
ALMEMO connectors incorporate two snap-lock levers; these snap into posi-
tion as soon as the connector is inserted into the socket, thus preventing unin-
tended disconnection if the cable is accidentally pulled. To withdraw the con-
nector, both these levers must be pressed in at the sides.

8.2 Measuring inputs and additional channels

Measuring circuit board MM-A9 has 9 input sockets (6c) to which initially mea-
suring channels M0 to M8 are allocated. However, ALMEMO
required, provide up to 4 channels with 9 input sockets each so that altogether
36 channels are available. The additional channels can be used in particular for
humidity sensors with four measuring variables (temperature / humidity / dew
point / mixture ratio) or for function channels. Each sensor can if necessary be
programmed with several measuring ranges or scaling settings; and two or
three sensors, if pin assignment so permits, can be combined in a single con-
nector (e.g. rH / NTC, mV / V, mA / V, etc.). The additional measuring channel
numbers per connector 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
A further innovation on this device is its four additional device-internal channels.
The first of these M9 is programmed by default as differential channel M1 – M0.
This only applies, however, if there are two sensors with the same units and
same decimal point position connected at measuring points M0 and M1. How-
ever, all four channels can be programmed with any other function channels
(e.g. U-Bat, cold junction compensation, average, volume flow, etc.); (see Man-
ual 6.3.4). The reference channels used are by default Mb1 = M1 and Mb2 =
M0 but this can be modified (see Manual 6.3.4).
The advantage of device-internal channels is that when using several sensors
for the same application these sensors do not have to be reprogrammed and
20 ALMEMO
®
sensor can be connected to the input sockets on
Manual includes detailed descriptions of the comprehensive
® 5690-2M
®
connector. Other compact modules
®
instruments (see Manual Ch 4). All
®
connector usually have the measuring
®
sensors can, if