SDM-CVO4 4-Channel Current/Voltage
Output Module
The SDM-CVO4 is a synchronously addressed datalogger peripheral designed to allow the
datalogger to output variable voltage or current signals under program control.
Figure 1. SDM-CVO4 (shown without mounting brackets)
1. Introduction
The SDM-CVO4 expands the analogue output capability of Campbell Scientific
dataloggers. Each output can be set to 0-10V or 0-20mA by the datalogger. The
output can be scaled and limited to 4-20mA by the datalogger program if required
by the application.
Typical applications will include driving remote ‘current-loop’ display units, re-
transmitting measured values to industrial control systems which have current or
high voltage inputs, sending control signals to valve controllers and providing
excitation voltages or currents to external sensors.
Each output is isolated both from the datalogger and the other channels on the
CVO4, thereby avoiding ground loop problems that might otherwise occur.
In the current mode the output can either act as a 2-wire current controller, where
the loop is powered from a remote voltage source, or it can be used to generate a
0-20 mA current source using a voltage output derived from its own power
supply.
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