How to transmit 6 packets in S130 Uart central

Hi there,

I am struct for two days trying to send 6 packets of 20 bytes as central. I use ble app uart central sample from nrf5_sdk11.0 with nrf51 S130 v2.0 softdevice.

I start believing that this sample and softdevice can only transmit 3 packets per connection interval. As I debug in the central side, it can only execute write command with out response 3 times then a buffer full occurs. When I get the sd_ble_tx_packet_count_get during connection it is only 3. I expect that is 6...for 6 tx? I also monitor the write event in the peripheral side I can only get 3 write interrupt.

I try to use the sd_ble_opt_set(BLE_COMMON_OPT_CONN_BW, &ble_opt) setting the tx and rx bandwidth to BLE_CONN_BW_HIGH but won't work out. I use this API during stack initialization and also right after sd_ble_gap_connect. It seems it only accept BLE_CONN_BW_MID

What would be my configuration to make to transmit 6 packets per connection interval. My connection interval is only 100msec and using S310 version 3.0 in the peripheral side.

Thank you for helping me out. -Mc