Trouble configuring DIO change detection sampling on Xbee Wifi

I am working with a new Xbee Wifi module (XB2B-WF) running firmware version 2026, and using the Xbee Wi-Fi RF Module S6B User Guide (90002180 M) as a reference.

I want to configure the module to send a DIO sample packet to a host via WiFi whenever a monitored digital input changes, and I have been unable to get that to work. I have successfully configured periodic sampling but I have been unable to get change detection to work.

For periodic sampling my pertinent settings are:

D1: 03
IC: 0000
IR: 07D0

With this setup I get a DIO sample every two seconds and I can see the changes in state of DIO1 in the data packet as expected.

For change detection sampling I changed the settings to:

D1: 03
IC: FFFF
IR: 0000

With these settings I see no DIO samples at the host. I have also tried with both periodic and change detection sampling enabled but I only see the periodic packets. I have tried this in both transparent and API modes but that seems to make no difference to packets sent out over the WiFi network.

If I understand the above mentioned user guide correctly this should work. Can anyone tell me what I am missing?

I found my problem. I had incorrectly set register DO to 0x04 while it should have been 0x08. I’m not sure why periodic sampling worked at all. When I corrected this register the change detection sampling works as expected.