2 operation with communications, Operation with communications -2, Table 15-2. file transfer times using pakbus -2 – Campbell Scientific CC5MPX and CC5MPXWD Digital Network Cameras User Manual

Page 96

Advertising
background image

Section 15. Power Calculations and Timings

15-2

15.2 Operation with Communications

The power calculations are more complicated when communications are
involved, as the amount of time the camera is in the Fully On active state is
increased by the amount of time it takes for the camera to transfer an image or
video.

The transfer times are influenced by two main factors: the size of the image
and the transfer speed used to send the image. The amount of time the camera
is on will be increased as the size of the image becomes larger or as the
communication rate slows down.

To properly determine the power consumption when using communications,
the additional time the camera consumes the Fully On Active Current Draw
needs to be accounted for in the power calculation. Refer to TABLE 15-2 as a
guideline for determining the amount of time it takes to transfer files using RS-
232 or RS-485 PakBus Communications.

TABLE 15-2. File Transfer Times

Using PakBus

Communication

Baud Rate (bps)

Time (Seconds)

per 100 kbytes

9600

240 seconds

0.0123 A-Hrs

19200

120 seconds

0.0076 A-Hrs

38400

60 seconds

0.0052 A-Hrs

57600

40 seconds

0.0044 A-Hrs

115200

30 seconds

0.0038 A-Hrs

To estimate the power consumption of the system look up the parameters in
TABLE 15-1. Power Consumption Table along with the communication times
to calculate the power consumption as follows:

• Determine the total Active Time in Minutes:


Active Minutes = Number of Pictures Per day *(Active Duration +
Communication Time)/60

For example, suppose a camera is in the Deep Sleep state. If it sends 24
100-kbyte images per day at 115200 bps, the camera is active for:

Active Minutes = 24*(25 seconds + 30 seconds)/60 = 22 minutes/day of
active time.

• Determine the total time in the Quiescent Low Powered State


Quiescent Minutes = 1440 minutes per day - active minutes
Quiescent Minutes = 1440 – 22 = 1418 Minutes

Advertising