Cannot send data after RTC wake up

[KHLau]

Hi, I use S110 to develop a product which will send data to master every 30s. I registered a 30s App timer at RTC1. When this event occurs, I can control the IO pins but cannot send out any data. Do I need to turn on the radio first before sending data? Which command should I use? Please help. Thanks.

The followings are the parameters I used.

#define MIN_CONN_INTERVAL               MSEC_TO_UNITS(500, UNIT_1_25_MS)
#define MAX_CONN_INTERVAL               MSEC_TO_UNITS(1000, UNIT_1_25_MS) 
#define SLAVE_LATENCY                   0 
#define CONN_SUP_TIMEOUT                MSEC_TO_UNITS(4000, UNIT_10_MS)

Sending data command used:

ble_nus_string_send(&m_nus, p_data, length);

[Ole Bauck]

Are notification on the RX characteristic enabled? This is normally done by the central. If notification is not enabled ble_nus_string_send(..) will return NRF_ERROR_INVALID_STATE. Can you check the return value of ble_nus_string_send(..)?