FlexRadio Systems Knowledge Center
Home
Search
Tags
Glossary
Members
Welcome Guest
(
Login
)
Latest Additions
Most Popular
Getting Started
Knowledge Base
TroubleShooter
FAQs
Downloads
FlexRadio Web Site
Community
Technical Support
Home
»
Knowledge Base
»
FLEX-5000 Transceivers
»
Firewire Interface
»
How to Use the FlexRadio Firewire Driver DPC Latency Checker to...
How to Use the FlexRadio Firewire Driver DPC Latency Checker to...
How to Use the FlexRadio Firewire Driver DPC Latency Checker to...
How to Use the FlexRadio
Firewire
Driver DPC Latency Checker to Determine Operating Mode
System Dependencies
Minimum
PowerSDR
Version:
N/A
Applicable Hardware:
Any
SDR
using the FLEX
Firewire
driver
Content provided by:
FlexRadio Systems Engineering
Version 3.4.0.5254 and above of the FlexRadio Systems' FLEX
Firewire
driver has a very accurate DPC (
deferred procedure call
) analysis tool that will automatically estimate the proper
WDM
operating mode for the
Firewire
driver for both Windows XP and Vista (32 & 64-bit).
In order for the DPC Latency Checker to provide an accurate assessment of the recommended operation mode, you
must
check your system with all of the applications you would normally be using
at the same time with your FlexRadio
transceiver
.
So
if
you use a logging program, digital mode programs, e-mail clients, web browsers and
PowerSDR
specific third-party utilities such as the VoiceKeyer and DDUtil (just to mention a few) at the same time with
PowerSDR
these programs
must be loaded and fully operational
(not just sitting idle) along with
PowerSDR
running.
Also, you need to run the DPC Latency Checker
for at least 5 minutes
to get a sufficient sampling duration for the results to be accurate as possible. A test duration period longer than 5 minutes is even better.
Even though the DPC checker may indicate that you can use the Normal operation mode, is still
highly
recommended that you use
Safe Mode 1
as the Operation Mode. DPCs are only one component that can adversely effect the performance of a real-time audio processing application such as
PowerSDR
. Normal mode operation is only recommended
if
the
PC
and all of the programs running on it do not induce long duration DPC, such as when you use a dedicated
PC
environment to run
PowerSDR
.
If
you do receive audio drop outs and program freezes when operating with the normal mode, immediately revert to the recommended Safe Mode 1 setting.
To determine your preferred operating mode, double left click on the FLEX
Firewire
Control Panel icon to open the Control panel.
In the Global Settings area, click on the
DPC
button at the top left of the screen
Left click on the radio button labeled "
Enable DPC Latency Checker
"
You will see the DPC latency values displayed in the box below the linear time scale and the Recommended
WDM
Operation Mode box will be populated with the suggested operating mode. In the example below the Max Latency is 81 microseconds (us) and the recommended
WDM
Operation Mode is Normal Mode.
The Operation mode will automatically be set to the recommended value.
To reset the DPC test, click on the
Reset
button. You may want to run several tests with different third-party applications running to determine which ones are more likely to result in long duration DPCs. Microsoft Outlook is one program known to be very bad for initiating long duration DPCs.
You can always over-ride the suggested Operation mode and select a mode that is more forgiving of longer duration DPCs and can provide a more stable operating environment for the FlexRadio
transceiver
.
If
you experience audio "freeze ups" or slight glitching of the received audio, change the Operation mode to one of the Safe Mode values.
This KB article may reference additional files that are available on the FlexRadio Systems web site Downloads page. Please use the URL(s) below to download the referenced materials.
An Adobe Acrobat Reader may be required to open the file. You can download Adobe Acrobat from here.
KB Source Document(s):
None Referenced
Rate this Article:
Add Your Comments
Comment require
login
or
registration
.
Details
Last Modified:
Saturday, April 18, 2009
Last Modified By:
Administrator
Type:
HOWTO
Rated 4 stars based on 3 votes.
Article has been viewed 13,002 times.
Options
Print Article
Bookmark Article
Social Bookmarks
Comments RSS
Powered By InstantKB.NET 2.0.6 © 2021
Execution: 0.234.
16 queries.
Compression Disabled.
Search All
Go
Advanced Search
Social Bookmarks...