Difference between ble parameter update functions

[q]

Could someone explain the difference between the following functions:

ble_conn_params_change_conn_params(ble_gap_conn_params_t *new_params) sd_ble_gap_conn_param_update(uint16_t conn_handle, ble_gap_conn_params_t const *p_conn_params)

My PCA10040 is operating as a peripheral. I'm trying to update the connection interval but have been unsuccessful thus far. Not sure which of the above two functions to use/why. I've seen forum posts use both to with regards to the connection interval.

SDK 13 PCA10040

[FormerMember]

Both of the functions will do the same job, ble_conn_params_change_conn_params() uses sd_ble_gap_conn_param_update() to update the connection parameters.

ble_conn_params_change_conn_params() is a function in the "BLE connection parameter negotiation library".