Campbell Scientific SDM-CVO4 4-Channel Current/Voltage Output Module - Manual (Page 8)

SDM-CVO4 4-Channel Current/Voltage Output Module
Maximum recommended
continuous operating voltage: 240 VAC RMS differential between an output
and datalogger ground - providing all issues
relating to local regulations for safe installation
and operation are followed (see section 4.5,
safety issues).
3. Power Considerations
The SDM-CVO4 power requirements are large compared to most Campbell
Scientific products, especially when driving significant loads. Care must be
taken to ensure that the power supply can cope with this higher demand.
Alkaline batteries are not recommended for long term applications.
The SDM-CVO4 has two internal power supplies, one for channels 1 and 2
and one for channels 3 and 4. It will only turn on the power supply for
channels 3 and 4 if sent an instruction that sets the output of those channels. If
channels 3 and 4 are not used the power consumption is approximately 20 mA
lower than when all outputs are used.
Where supported by the datalogger, and when the application allows it, the
SDM-CVO4 can be shut down to reduce its consumption to less than 0.5 mA.
In this state all outputs are switched off.
4. Installation
Prior to installing the device you need to set the output mode (current or
voltage) of each channel by positioning internal jumpers (see section 4.3). You
also need to set the SDM address of the module (see section 4.4) and
additionally consider any safety issues specific to the installation (see section
4.5).
4.1 Connection to a Datalogger
For datalogger connections, see Table 4-1, below.
TABLE 4-1. Datalogger to SDM-CVO4 Connections
Connection Order SDM-CVO4 Datalogger Function
First 12 V 12 V on datalogger or external supply Power
Second
or G or G
Common Ground
C1 SDM-C1 (CR3000, CR5000) or C1 (other dataloggers) Data
C2 SDM-C2 (CR3000, CR5000) or C2 (other dataloggers) Clock
C3 SDM-C3 (CR3000, CR5000) or C3 (other dataloggers) Enable
Multiple SDM-CVO4s may be wired in parallel by connecting the SDM and
power connections from one SDM-CVO4 to the next.
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