User`s manual

VPort 2141 Video Encoder User’s Manual Troubleshooting
7-3
Q: Why can’t I watch video from the VPort 2141 after it is authenticated?
A: There are several scenarios that could cause this problem:
1. If you have just installed the VPort 2141, and are unable to watch the video, check if the
video input is enabled, and check the video modulation on the Configuration page.
2. If the VPort 2141 is installed correctly and you are accessing the VPort 2141 for the first
time using Internet Explorer, adjust the security level of Internet Explorer to allow
installation of the plug-in.
3. If the problem still exists after making the adjustment, the current number of users could be
greater than what the system allows.
4. If you are using a demo account, the administrator may have hid the video from public view.
Q: How can I use a url instead of IP address to connect to the VPort 2141?
A: To allow users to connect to the VPort 2141 through an easily memorized name, administrators
must first configure the network’s domain name server. Here is an example: the administrator
installs the VPort 2141 with a reserved IP address and assigns it a name on the domain name
service, then users can connect to the VPort 2141 by typing the web address instead of an IP
address. If there is a DHCP service on the network, the IP address must be excluded in the
DHCP service to prevent an IP conflict.
Q: What is the plug-in for?
A: The plug-in provided by the VPort 2141 is used to display motion pictures on versions of
Internet Explorer that do not support server push technology. If your system does not allow
installation of any plug-in software, the security level of the web browser may need to be
lowered. It is recommended that you consult the network supervisor in your office to adjust the
security level.
Q: Why is the timestamp different from the system time of my PC or notebook?
A: The timestamp is based on the system time of the VPort 2141. It is maintained by an internal
real-time clock, and automatically synchronizes with the time server if the VPort 2141 is
connected to the Internet and the function is enabled. Differences of several hours may result
from the time zone setting.
Q: Why does the image not refresh regularly?
A: In a modem environment, this is because the bandwidth of PPP connections is much lower than
for Ethernet. If the difference of the timestamp is not stable, use the modem property on the
control panel to adjust the UART FIFO to a lower level for both receiving and transmitting. In
an Ethernet environment, it may be due to the time taken for storing snapshots into memory
when events occur.
Q: How many users are allowed to watch the VPort 2141 at the same time?
A: To achieve the best effect, the VPort 2141 will allow a maximum of twenty users to connect at
the same time. Excess users can get an auto-refreshed still image on the homepage instead. It is
recommended to build another web server to host a large quantity of users by retrieving images
from the VPort 2141 periodically.
Q: What video rate does the VPort 2141 support?
A: The JPEG codec can process 30 frames per second internally. However, the overall
performance is subject to many different factors, such as:
1. network throughput
2. bandwidth share
3. number of users
4. number of video inputs accessed at one time
5. viewing complicated objects results in a larger image file