ANT Forum

I have an application with one master device and two slave devices.

Master will open an channel and two slaves will be searching at the same time.

Both slaves both will be synced to the master on that single channel slot.

Is there anyway to tell this two channels actually is using one time slot?

What I want to do is, if this happens, I want to break one channel and open another channel on the master to create a separate channel with the other slaves. So that both slaves can talk to the master independently.

Thanks

Paul      

Thanks Harrison and OMB
I am using 3 ANT dongles to do more experiment.

I think according to how ANT works. Two slaves synced to one master channel is absolutely normal and no way to make any of the parties aware there is a second slave exist in the system.
Please confirm my understanding is correct.

I sent some ACK broadcast data from all 3 units by pressing buttons on the screen. The result is what I expected, they all succeeded.

I believe is I did the send from two slaves exactly at the same time, one of the slave unit would have failed.

The "problem" here is the acknowledge packet is exactly same from different slaves, so the master doesn't know at all which slave is responding, otherwise I believe there is something I can do in the application layer to handle this.

I think Harrison is right, for this type of application the only way is to use shared channel.
I will revisit the shared channel application, I believe there is a mechanism in the application that handles multiple slaves fighting for it and eventually all the slaves will get an address as the system designed for.

Thanks

Paul      

Hi Harrison

I understand your comment about different channel IDs.
I believe this is the right direction. I will design a custom handshake between master and slaves for each slave to negotiate for its own channel with the master.

Thanks

Paul

Harrison - 21 April 2016 03:49 PM

Hi Paul,

The only way you can tell which channels are sync'd to what is by using the channel ID parameters (device number, device type, and transmission type fields).

You can change one of these fields on a new master channel and then set the slave to sync to that channel instead (close channel, set channel ID, open channel).

You could also use a shared channel scheme to let the master channel act as a polling device (this is described in the "ANT AN Auto Shared Channel Master Example" app note.

It is not recommended to run master channels with the same channel ID. If you do attempt to run multiple master channels with the same channel ID, the slave channels will not be differentiate between them.

Cheers