Where:
Vmin - The minimum required supply voltage
Vt - The minimum required voltage specified for the connected
transmitter (at load=0)
Rs - Total loop load including leads' resistance and PLC's input impedance
Example:
The minimum operational voltage of a given transmitter is 12V.
The total loop load is 250
W
.
Solving the above voltage:
Vmin= 24Vdc
6. CONNECTING THE TRANSMITTERS TO THE MULTIPLEXER
6.1 TWO-WIRE TRANSMITTER
A Two-Wire transmitter is connected
so that its positive terminal is connected
to the "V" terminal, and its negative
terminal is connected to the "I" terminal.
(see fig 2.)
Figure 2.
6.2 THREE-WIRE TRANSMITTER
A Three-Wire transmitter is connected
so that its positive terminal "+V" is
connected to the multiplexer "V" terminal,
its negative terminal "-V" is connected
to the multiplexer's "COM" terminal and
the current output terminal "Io" is
connected to the DRA-CSM-1 "I"
terminal. (see fig 3).
4
Figure 3.
