Fastec IL3, Operator'S Manual

Page: 82 / 107

IL3 User’s Guide
page 74
11S-3002B
When the PC is Too Busy:
Referring to Table 7-3, you will notice that for several of
the transfers there are missing frames and packets.
These were downloads of only 188 frames, which should
be very easy considering that FasMotion reserved 250
buffers--more than enough to buffer the entire transfer.
The Min (minimum buffers) never got close to the
Backoff number, so the Fas
M
otion never got a chance to
slow the camera down before it started missing frames.
To understand what happened here, it is helpful to look
at the performance tab in Task Manager. Notice in Figure
7-12 that the “Free” memory has gone to 0. This means
that, having no more physical memory, the system is
going to slow down. It will not be able to service the
application properly.
What is happening here is that the system is very busy.
To create this example, the computer used had about a
dozen applications open.
It is common to have a lot of applications and services
running “in the background” on a computer. In order
to get consistent high-speed file transfers from Fas M otion it is very important to have as little else
running on the PC as possible.
Note: In each instance on the table, all of the frames were successfully saved as the system
automatically retrieves any “missed frames” at the end of the download.
Use Jumbo Packets!:
Referring to Table 7-4, using Jumbo Packets (sometimes called Jumbo Frames) can make a big
difference. You may find that a larger packet delay is required with Jumbo Frames, but because the
packets are bigger, there are fewer of them, and fewer delays as well.
In this example there was about a 3x improvement in transfer rate simply by using Jumbo Packets.
Duration
h:m:s:dec
Bytes Speed
MB/s
Miss-
Frames
ROI Good -
Frames
Pkt -
Size
MissPkts PktDly Buffer Backoff Min Drv Ext
0:0:6:650 26573616 4.22376 0 1280x1024 188 1500 0 180 250 125 236 C: AVI
0:0:33:468 246528160 7.12447 0 1280x1024 188 1500 0 180 250 125 247 C: DNG
0:1:40:407 739256608 7.0501 5 1280x1024 188 1500 9708 180 250 125 248 C: BMP
0:0:7:611 26563368 3.61897 3 1280x1024 188 1500 280 180 250 125 216 C: JPG
0:1:41:698 739300976 6.98072 5 1280x1024 188 1500 5354 180 250 125 247 C: TIF
0:0:33:951 246468752 7.12276 1 1280x1024 188 1500 578 180 250 125 247 C: TIF
Table 7-3: Missing Frames on a Busy System
Figure 7-12: Memory Usage in Task Manager
Duration
h:m:s:dec
Bytes Speed
MB/s
Miss-
Frames
ROI Good -
Frames
Pkt -
Size
MissPkts PktDly Buffer Backoff Min Drv Ext
0:0:28:484 484259096 16.4938 0 1280x960 394 1500 0 40 200 100 196 F: tif
0:0:28:156 484259096 16.4938 0 1280x960 394 1500 0 40 200 100 195 F: tif
0:0:9:438 484259096 51.3139 0 1280x960 394 9000 0 40 200 100 182 F: tif
0:0:26:734 1317578048 48.3285 0 1280x960 1072 9000 0 40 200 100 105 F: tif
0:0:47:203 2443418992 49.5793 0 1280x960 1988 9000 0 40 200 100 190 F: tif
Table 7-4: Benefit from Jumbo Packets