111
STYLE="width:40px;top:635px;left:134px;position:absolute"
onmousedown="ZoomControl(0)" onmouseup="mouse_up()" onmouseout="mouse_up()">
<INPUT TYPE="BUTTON" NAME="WIDE_BTN" VALUE="-"
STYLE="width:40px;top:665px;left:134px;position:absolute"
onmousedown="ZoomControl(1)" onmouseup="mouse_up()" onmouseout="mouse_up()">
</FORM>
</BODY>
</HTML>

8.6. Notes

- Enable the JPEG/MPEG-4 frame size that you want in “Basic Settings2” or “Encoding” page of VN-V686/685/686B.
- Start Multicast stream on VN-V686/685/686B Web page to use Multicast. The ActiveX control does not send request
to VN-V686/685/686B for starting Multicast stream.
- Set unique Multicast address and port number to each Multicast stream if multiple multicast streams are required in
the system.
- Reload of ActiveX control is required to change Multicast property.

9. FAQ
(1) Low Frame rate due to long delay of network
- Causes of Low Frame Rate
During transmission via TCP, VN-V686/685/686B sends out the following data by receiving the Ack of TCP. When
network delay is long, reception of Ack will be delayed and sending rate will drop. This therefore leads to a drop in the
frame rate.
- Countermeasure
This problem can be avoided by receiving via multicast. Multicast uses UDP and Ack does not exist. As such, the
sender will be able to continue sending without being affected by network delays.