ANT Forum

Hi,

I have created a program using C# that displays hearts rates on a screen in real time in a group format. I have a database of our HRM device numbers. In the program people are assigned one of our known HRM device number's and I use continuous scanning mode to pick up the HRM devices. I then match the heart rate to the correct person based on the HRM device number that is picked up and the HRM device number that they are assigned. It has been working well until we got some more HRM's whose device numbers are the same as those we already have. Is it possible to change the HRM's device numbers (I read that if you take out the battery on certain models it regenerates the number but that doesn't work on the models we have)? Or to get a manufacturer ID/more detailed way to uniquely identify a HRM device in continuous scanning mode?

Thanks      

Note: I am currently getting the device number from the ANT_ChannelID.getDeviceIDfromExt() function      

Boblcukman - 06 January 2016 11:40 AM

Hi,

I have created a program using C# that displays hearts rates on a screen in real time in a group format. I have a database of our HRM device numbers. In the program people are assigned one of our known HRM device number's and I use continuous scanning mode to pick up the HRM devices. I then match the heart rate to the correct person based on the HRM device number that is picked up and the HRM device number that they are assigned. It has been working well until we got some more HRM's whose device numbers are the same as those we already have. Is it possible to change the HRM's device numbers (I read that if you take out the battery on certain models it regenerates the number but that doesn't work on the models we have)? Or to get a manufacturer ID/more detailed way to uniquely identify a HRM device in continuous scanning mode?

Thanks

To my best knowledge the ANT protocols need unique device IDs in order to work properly.
And I'm not aware that you can change the device ID of (Garmin) HRM straps.
So I'd suggest to test your straps for unique IDs before adding them to your pool.

Cheers,
OMB      

Thank you for the reply,

Unfortunately the area where the program is being used has people who are wearing their own devices but are not apart of the class. Having to move the class to another area is an inconvenience we are trying to avoid.

5.3.4.3 of the ANT Device Profile Heart Rate Monitor states

5.3.4.3 Serial Number Determination
The 16 bit device number allows a unique identification of the device in the RF domain, but cannot uniquely identify all
manufactured heart rate monitors. When used in combination with the Manufacturer ID and the upper 16 bits of the serial
number transmitted in this message, a unique identification of the heart rate monitor can be made.
The 32-bit serial number comprised of the upper serial number (most significant 16 bits) and the device number (least
significant 16 bits) provides more than 4 billion serial numbers for each manufacturer ID. The manufacturer must ensure
that this data is unique for each heart rate monitor produced.
It is important to note that the device ID must never be 0, therefore serial numbers that are integer multiples of 65536
must not be used. See section 4.2.2 for more details.

The manufacturer ID/serial number is sent in data page 2, which is a background data page that is sent atleast once every 64 messages. Is it possible to get the manufacturer ID/serial number or some other unique identifier that I can use with the device number more often than every 64th message? So I can continue to display the heart rates in as real time as possible rather than updating it only every 16 seconds (HRM transmits at about 4Hz)?      

Hi Boblcukman,

The group display use-case is something we are giving some thought to right now. We'll have an ANT+ HRM Device Profile update coming out that documents this that you should look out for.

Beenish Khurshid
ANT+ Applications Engineer      

Thank you for the reply,

When is the ANT+ HRM Device Profile update expected to come out?

Thanks      

Within the next few months.