XBEE S2 ADC sample on input change

XBee & XBee Gateway
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1

(newbie to XBEE )

I have established a working mesh with XBee S2 modules, several routers and a co-ordinator.

I am monitoring 2 digital inputs for change, DIO0 and DIO1 and when a change is detected I want to read the status of all my digital IO and one ADC ( AD2 ).

I am using API mode.

When a change is triggered with a pushbutton on either DIO0 or DIO1 I successfully transmit and detect a 0x92 frame to the co-ordinator. The frame does not contain any analog data however. ( Analog channel mask is 0x00 and the byte stream terminates after the digital sample bytes and checksum )

To check operation I have set an automatic sample cycle ( 5 seconds ) and the 0x92 frames that are triggered automatically contain both digital and the correct Analog data. ( channel mask = 0x04 and a word of analog data as expected )

According to this KB article - http://knowledge.digi.com/articles/Knowledge_Base_Article/Digital-and-analog-sampling-using-XBee-radios my digital IO change should automatically read and package the analog channel into my 0x92 payload.

Am I missing something?

2

To answer my own question.

It turns out that the XBEE S2 modules can’t do this.

IC triggered samples only include digital data samples and not analog data so it is impossible to have a mesh that simply transmits analog values on a self initiating basis without having a processor at the outboard point or by polling the endpoints from the coordinator.