Campbell Hausfeld CC640 - Manual (Page 34)

CC640 Digital Camera
Refer to Section 4.2 for additional information and connections diagrams using the
RS-232 port.
10.2.4 RS-485 Communications
The camera can download images via its RS-485 port using the PakBus protocol.
An MD485 can be used to transmit images via PakBus from a camera to other
devices:
• Set the parameter PakBus Port to RS-485
• Set the parameter PakBus Address to a unique value in the PakBus
network.
• Set the parameter PakBus Destination Address to the device that is
intended to retrieve the images.
• Set the RS-485 BAUD rate to match the BAUD rate of the RS-485
network that the camera is being connected to.
Refer to Section 4.4 for additional information on the RS-485 port.
10.2.5 Concurrent Communications
PakBus allows the camera to download images to a datalogger simultaneously
with other datalogger communications. A communications task will take longer if
the datalogger is communicating with multiple devices at the same time.
It may be beneficial to set up the system to avoid image transfers when other
communications are scheduled.
For example, longer connect times on long distance telephone connections can be
avoided by scheduling image transfers from the camera to the datalogger outside
the scheduled data collection time. If a station is called on the hour to retrieve
data, image acquisitions could be initiated before the scheduled call (15 minutes
prior) to shorten the connect times.
11. Power Calculations and Timings
The CC640 was specifically designed for operation in power-constrained systems
such as solar powered sites. It is critical in such systems that the power switch on
the camera always be left in the AUTO position to take advantage of the low
power mode. This section outlines power consumption of the camera for purposes
of power supply design for a system.
11.1 Standalone Operation
In standalone mode the camera operates as a self-contained image logger.
The current draw of the camera while in low power quiescent mode is 250uA.
When the camera wakes up to take a picture, operating current draw increases to a
maximum of 250 mA for approximately 30 seconds. In order to calculate the daily
power usage of the camera, both the quiescent and operating power consumptions
need to be calculated.
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