Campbell Scientific CDM-VW300 Series Dynamic Vibrating-Wire Analyzer System - Manual (Page 55)

CDM-VW300 Series Dynamic Vibrating-Wire Analyzers
FIGURE 7-15. CR3000 and SC-CPI connections
SC-CPI module connects to terminals C1, C2, C3 (not SDM-C1,
SDM-C2, SDM-C3). NOTE
7.7.7 Maximum Number of Analyzers on a Datalogger
The maximum number of active CDM-VW300 or CDM-VW305 analyzers
and channels that can be managed by a single datalogger is a function of the
dynamic sample or scan rate. The following table lists example configurations
that have a full complement of analyzers.
TABLE 7-3. Number of Analyzers and Channels Supported by a
Datalogger Writing to CF Card
Measurement
Rate
CR3000
Datalogger
CR1000
Datalogger
CR800
Datalogger
20 Hz
48 Channels on
6 CDM-VW305s
32 Channels on
4 CDM-VW305s
32 Channels on
4 CDM-VW305s
50 Hz
24 channels on
3 CDM-VW305s
8 channels on
1 CDM-VW305
8 channels on
1 CDM-VW305
100 Hz
8 channels on
1 CDM-VW305
Not supported Not supported
These channel counts predict best case scenarios wherein no other
measurements are made on the dataloggers. Additional measurements will
likely reduce the channel counts.
Note that each analyzer uses the bandwidth of the full channel compliment
whether or not all channels are active. For example, consider a CR3000
datalogger controlling eight CDM-VW305 analyzers with two active channels
on each analyzer making measurements at 20 Hz. The number of active
channels is 16, but the system fails because the maximum number of analyzers
(6) has been exceeded, even though the maximum number of channels has not.
Two notes about CR1000 and CR800 dataloggers with a full analyzer
compliment:
• Final storage will significantly lag behind real time — several minutes in
some cases.
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