First GATT write event on BLE connection

[Bryan V]

I have Bluetooth iOS app communication with my nRF51822. I notice that when I connect the the nRF, the first GATT write event is always the same:

p_ble_evt->evt.gatts_evt.params.write.handle = 0x000B

I'm thinking this is some system generated event from the SoftDevice since does not match any handle for any characteristic I added during initialization. But does anyone have any idea what/where this write event is getting generated from?

Thanks!

[Petter Myhre]

I'm guessing it is the CCCD of one of your characteristics. You could check with Master Control Panel.