Ahlborn ALMEMO 2690-8A, Руководство по эксплуатации

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8.
CONNECTION OF THE TRANSDUCERS
Any ALMEMO® sensors can be connected to the ALMEMO® input sockets M0
to M4 of the measuring instrument (1). For connecting existing sensors it is only
necessary to connect a corresponding ALMEMO® connector.
8.1
Transducers
A detailed description of the comprehensive ALMEMO® sensor range (see man-
ual section 3) and the connection of existing sensors (see manual section 4) to
the ALMEMO® instruments are provided in the ALMEMO® manual. All standard
sensors with ALMEMO® connector usually have the measuring range and di-
mension already programmed and can be immediately connected to any input
socket. A mechanical coding ensures that sensor and output modules can only
be connected to the correct sockets. Furthermore, each ALMEMO® connector
has two locking levers that snap in when the insertion into the socket is estab-
lished and that prevent a disconnection caused by pulling the cable. Both levers
must be pressed on the sides for disconnecting the connector.
8.2
Measuring inputs and Additional Channels
The measuring instrument ALMEMO 2690-8 has 5 input sockets (1) that the
measuring channels M0 to M4 are initially allocated to. However, ALMEMO®
sensors can, if required, provide up to 4 channels so that 20 channels are avail-
able with 5 input sockets. The additional channels can be especially used with
humidity sensors with 4 measuring variables (temperature/humidity/dew
point/mixture ratio) or used for function channels. If required, the sensor can
also be programmed with several ranges or scaling or, depending on the pin
assignment, 2 or 3 sensors can be combined in one connector (e.g. rH/Ntc,
mV/V, mA/V etc.). The additional measuring channels of a connector are in-
creased in steps of 10 (e.g. the first sensor has the channels M0, M10, M20,
M30, the second sensor has the channels M1, M11, M21, M31 etc.).
Device-internal channels:
An innovation on this device is its four extra additional channels. The first of
these M5 is programmed by default as differential channel M1 – M0. This only
happens, however, if there are two sensors with the same units and same dec-
imal point position connected at measuring points M0 and M1. However, all four
channels can be programmed with any other function channels (e.g. U-Bat, CJ,
average, volume flow, etc.); (s. 11.3.10, man. 6.3.4). Mb1 = M1 and Mb2 = M0
are always used as reference channels by default.