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28 February 2011 04:32 AM

b_bleier Newbie

Total Posts: 11

Joined 2010-11-25

Hello,

I am a firmware developer of the company http://www.spantec.at and we are developing an ANT network, called SWARM, for ANT+ and ANTFS devices. There is an upcoming interest from other companies to integrate their ANTFS devices into our SWARM network. However, we found out that more and more ANTFS devices have a strange behaviour when more (SWARM) ANTFS hosts try to get data from third-party ANTFS devices at the same time.

Following the ANTFS specification (Linking to only one device, authentication, ...) such a multiple access situation should already be solved, because the client chooses only one device. However, we found out that ANTFS manufacturers do not or cannot test such a situation.

Attached there is one case that I am working right now. A pedometer was accessed by three SWARM ANTFS hosts. After accessing successfully the transport layer the pedometer falls back into the authentication layer and tries to connect to another host without going back to the link layer. We are working closely with the manufacturer together to solve this problem, but we found out that other manufacturers have similar problems with multiple hosts.

My questions:
1) Is the ANT community already aware of this problem?
2) Are there already plans for integrating a feature into the simulator for testing access from multiple hosts to ANTFS devices?

Best regards
Berthold

28 February 2011 04:45 AM #1

b_bleier Newbie

Total Posts: 11

Joined 2010-11-25

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For some reason, I was not able to upload my file at the first time. So here is an ANTWARE screenshot of the above described case. [file name=Pedometer_Multiple_access_in_SWARM_2.pdf size=140499]http://www.thisisant.com/images/fbfiles/files/Pedometer_Multiple_access_in_SWARM_2.pdf[/file]

28 February 2011 09:44 AM #2

alejandra Moderator

Total Posts: 662

Joined 2012-10-09

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We do not have plans to incorporate such feature in the simulator, but multiple instances of the ANT-FS Host demo can be used to test scenarios like this and identify problems with ANT-FS client implementations.

After a client has progressed to the transport layer with a particular host, it should never return back to the authentication state. Once in transport state, the client should process download/upload commands until it is requested to DISCONNECT, or times out without receiving any commands from the host. In both of these cases, it should return to the LINK state. If a download request fails, generally, it should not disconnect right away, as it has to allow some time for the host to retry. Furthermore, a client should never establish a connection with a different host while in authentication state.

01 March 2011 02:16 AM #3

b_bleier Newbie

Total Posts: 11

Joined 2010-11-25

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Hello Alejandra,

thanks for our fast reply.

It took some time to find the ANTFS host demo on your website.

Now I know that I have to search in "Developer's Zone", "ANT+ Member Zone" and "ANT+ Adopter Zone" to have an overview of all ANT downloads.

I will try it out. I hope it works and we have a way that manufacturers can test their devices.

Best regards
Berthold

02 March 2011 01:47 AM #4

b_bleier Newbie

Total Posts: 11

Joined 2010-11-25

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Hello,

I made some tests with multiple instances of the ANT-FS host demo. I was able to detect some known multiple access bugs. However, the case described at the beginning of this topic seems to be too special to be reproducible with the ANT-FS host demos.

The hint with multiple instances is a good hint and in future we will suggest our ANT-FS device manufacturers to test this way to be suitable for our SWARM network.

Thank you for your hint Alejandra.

Best regards,
Berthold

PS: How can I close this topic?

02 March 2011 11:14 AM #5

alejandra Moderator

Total Posts: 662

Joined 2012-10-09

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Yes, we would certainly recommend all manufacturers implementing ANT-FS to make sure that their device works with the ANTFS Host or Client demo. The logs generated by the ANT-FS PC tools are quite useful in debugging while developing with ANT-FS.

ANT Forum

Testing multiple access to an ANTFS device with the simulator