Vivotek IP3111 User Manual page 94

Q. Why does the image not refresh regularly?
A. In a modem environment, it is because the bandwidth of PPP connection is far less than
Ethernet. If the difference of the timestamp is not stable, adjust the UART FIFO lower in
both receiving and transmitting from modem property in the control panel. While in
Ethernet, it may be due to time taken in storing snapshots into memory upon events
occurring.
Q. How does Network Camera detect the supported PTZ cameras automatically?
A. If there is no camera detected, Network Camera will monitor the CTS of the camera
control cable continuously. As long as the CTS is detected, Network Camera will try to
handshake with supported cameras until a supported camera is found. There is no more
camera detection once a PTZ camera is recognized.
Q. How many users are allowed to watch Network Camera at the same time?
A. Basically there is no limitation of users. However the video quality also depends on the
network bandwidth. To achieve the best effect, Network Camera will allow several users to
be connected. It is recommended to build another web server to host a large quantity of
users by retrieving images from Network Camera periodically.
Q. How fast is the video rate of Network Camera?
A. The MPEG4 codec can process 30 frames per second internally. However the total
performance is subject to many coefficients as follows:
1. network throughput.
2. bandwidth share.
3. number of users.
4. the complicated objects in view results in larger image file.
5. the level of your PC or notebook which is responsible for displaying images.
In general, the transfer rate in a general local network environment can achieve over 200
kilobytes per second and approximately 10 to 20 pictures of a normal environment per
second.
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