CAN BUS Shield

Hello, I’m trying to send a message with CAN BUS Shield.

I’m using this CAN BUS Shield

here is my code which i am using now

// demo: CAN-BUS Shield, send data
#include <mcp_can.h>
#include <SPI.h>

INT8U result; 

void setup()
  // init can bus, baudrate: 500k
  if(CAN.begin(CAN_500KBPS) ==CAN_OK) Serial.print("can init ok!!\r\n");
  else Serial.print("Can init fail!!\r\n");

unsigned char stmp[8] = {0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07};
void loop()
  // send data:  id = 0x00, standrad flame, data len = 8, stmp: data buf
  result = CAN.sendMsgBuf(0x11, 0, 8, stmp);
  delay(100);                       // send data per 100ms


As you can see a result, to transmit occurs only 3 times. (Success means that sending has done)

but after 3times, message can’t be sent.

Could you tell me why it happen?

I attach the picture of Arduino + CAN BUS Shield.

Is there anything I need to do more?

I’m in hurry, please help me.

Thank you