ANT Forum

When the ANT+ Display Simulator sends a calibration request to my sensor and the sensor responds with the calibration acknowledgement page, the Simulator sees some of my responses but does not see others. What are the timing constraints when the sensor responds to the calibration request from the display? Can the response page be asynchronous to the clocking TX_EVENTs from the C7, or should it replace a data page in the normal sequence? Is a timeout enforced by the spec, or only by the sensor design? Thanks.      

Hi dwilhide,

The display simulator does not filter the messages that it receives, so if you send the response then it should show up at the simulator (assuming it's not lost due to interference etc). There is no timeout for when the display stops listening for the response.

Are you waiting to see the Event_TX message after you write the calibration response message to the TX-buffer, before you try to send any other messages? If not, then you could simply be overwriting your response before it has a chance to be sent. (The TX-buffer holds one message at a time, and will send the contents of this message on each channel period. When you send a new message to ANT from the host application it simply overwrites the contents of this buffer.) If this sounds new to you, then take a look at section 9.5.5.1 in the ANT Message Doc, and in particular, figure 9.1 to see the sequence of events associated with broadcast transmission.

So putting this back into the phrasing you used, then yes, the calibration response should replace a data page in the normal sequence.