Campbell Scientific SDM-CVO4 4-Channel Current/Voltage Output Module - Manual (Page 10)

SDM-CVO4 4-Channel Current/Voltage Output Module
You cannot reliably insert more than one solid-core wire into one terminal
connector unless the wires are soldered or clamped together. When inserting
more than one stranded wire, twist the bare ends together before insertion.
4.2 Output Device Connections
For each output channel there are four terminals which are labeled V
o
, Id plus
there are two ground ( ) connections per channel. The two ground
terminals are internally connected; two are provided for convenience.
4.2.1 Voltage Output Mode
The V
o
terminal is the output for either the preset voltage signal, when the
channel is set to operate in voltage mode or an unregulated 15 VDC power
source in current mode.
In voltage mode the connection to a remote device is a simple two wire
connection:
+
–
Inputs
Remote Voltage Input
CVO4
V
o
4.2.2 Current Output Mode
The Id terminal acts as the input for the current that is to be controlled. In
current output mode you arrange to sink current into the terminal with a
positive current flowing relative to the ground terminals. (In voltage output
mode this terminal has no function.)
There are several different possible connections in current mode. As each
channel is isolated and floating, the method of connection to a remote device is
flexible. There are two different ways of powering the loop current.
a) The remote device powers the loop, where, depending on the ground
referencing requirements of that device, the connection can be as shown in
the diagrams below:
V+
Remote Voltage
Source +ve
Remote Current
Input
V-
CVO4
+
–
I
d
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