How could Nordic received large byte from phone

Question

Hi there, 
 How could I receive a large data from phone, example 120 bytes from a characteristic. So far I was able to receive 20 bytes. 
 From the working code of 20 bytes, I modified it so that it would receive a maximum data of sizeof(uint8_t) and change the location from stack to user(BLE_GATTS_VLOC_USER) but its not working.
It seems that i haven't receive anything from the BLE GATT WRITE EVENT. 
 If Characteristic wont able to received a large amount of data, will you please tell me on how to transfer a large amount of data to Nordic. 
 I am using S310 softdevice and nRF51422 chip. Thanks 
 below is my code. 
 static uint32_t add_char_command_type(ble_myplbs * p_lbs, const ble_lbs_init_t * p_lbs_init)
{
ble_gatts_char_md_t char_md;
ble_gatts_attr_t attr_char_value;
ble_uuid_t ble_uuid;
ble_gatts_attr_md_t attr_md; 
 memset(&char_md, 0, sizeof(char_md));

char_md.p_char_user_desc = (uint8_t *)CHAR_NAME_COMMAND_TYPE;
char_md.char_user_desc_max_size = 12;
char_md.char_user_desc_size = 12;
	
char_md.char_props.read = 1; 
char_md.char_props.write = 1;
//char_md.p_char_user_desc = NULL;
char_md.p_char_pf = NULL;
char_md.p_user_desc_md = NULL;
char_md.p_cccd_md = NULL;
char_md.p_sccd_md = NULL;

ble_uuid.type = p_lbs->uuid_type;
ble_uuid.uuid = SAL_UUID_CHAR_COMMAND_TYPE;

memset(&attr_md, 0, sizeof(attr_md));

BLE_GAP_CONN_SEC_MODE_SET_OPEN(&attr_md.read_perm);
BLE_GAP_CONN_SEC_MODE_SET_OPEN(&attr_md.write_perm);
attr_md.vloc = BLE_GATTS_VLOC_USER; 
attr_md.rd_auth = 0;
attr_md.wr_auth = 0;
attr_md.vlen = 0;

memset(&attr_char_value, 0, sizeof(attr_char_value));

attr_char_value.p_uuid = &ble_uuid;
attr_char_value.p_attr_md = &attr_md;
attr_char_value.init_len = sizeof(uint8_t); 
attr_char_value.init_offs = 0;
attr_char_value.max_len = sizeof(uint8_t); 
attr_char_value.p_value = ble_buffer_write; 

return sd_ble_gatts_characteristic_add(p_lbs->service_handle, &char_md,
 &attr_char_value,
 &p_lbs->command_type_char_handle);

bjorn-spockeli · Accepted Answer

You can use long writes to write to characteristics that are larger than 20 bytes, please see
 this post and the documentation of sd_ble_gattc_write 
 This Message Sequence Chart(MSG) may also be helpful. 
 -Bjørn 
 UPDATE: 
 Modified version of SDK v9.0 where the ble_app_hrs example has been modified to support long writes to the heart rate measurement characteristic. 
 nRF51_SDK_v9_0.zip