[NRF51822] connection related

[Terry]

I'm using NRF51822 and I have some question about the ble connection: according to BLE 4.0 spec, when Tsup(connection supervision time) reaches, connection lost is considered. but I've tried to stop send data from bi-direction(mater & slave) for a while(i'm sure this time is lager than Tsup) after I connect BLE device(NRF51822) with Master Control Panel. then I try to send data after the 'spare time', it can still success. Why would this happen? the connection doesn't loss? In addition, BLE 4.0 spec said that "If the procedure response timeout timer reaches 40 seconds, the connection is considered lost"(Vol6,section5.2). It makes me confused, when will connection loss occur? connection supervision timer reaches or procedure response timeout timer reaches 40 seconds?

[Terry]

Dear Ole Morten, thanks for your kindly reply. Sure, it must be that. Does it to say, once ble deviece(nrf51822) get into connection state(interference & other abnormal situation not to be considerd.), the connection will keep active all the time? I mean, doese it lost connection if device always answer empty packets?

Another question, I'm using uart to transmit datas between PC and my MCU via 51822, see the attached picture.

[Ole Morten]

As long as the devices are within RF range of each other, the connection should not be lost, except in cases of (strong) interference or similar.

As for the UART, this should not be any problems as long as you make sure that your UART interrupt runs on a legal interrupt priority (1 or 3, not 0 or 2). When using the sd_nvic_* API instead of NVIC_* directly to enable the interrupt, this will be checked for you.

The reason you cannot add images as a comment is that separate questions should be posted separately instead of combining them as here. If you found my other answer useful, I'd be happy if you could click the "Accept as answer" button below it to mark this question answered. :)