Cannot read data from UHF RFID Sensor Tag SL900A

#define  SEN     PORTC.B1
#define  WRITE   0x0000
#define  READ    0x4000
#define PAGE_WR  0x0800
unsigned int uiTemp=0;


//Write function for the SPI interface
void SL900A_Write(unsigned int uiMode, unsigned int uiAddress, unsigned char ucData){
     SEN = 1;              //Enable Slave select
     delay_us(500);          //SEN to first SCLK rising edge setup time
     //Transmit 16 bit data
     uiTemp = (uiMode&0xff00) | uiAddress;
     SPI1_Write(uiTemp);
     SPI1_Write(ucData);                        //Data need to transmit
     delay_ms(1);
     SEN = 0;                                   //Stop
}

void main()
{
     unsigned char ucwrData, ucMo;
     unsigned int uiMo, uiAdd,i,uiTemp1;
     
     //FOSC = 0b110; INTOSC oscillator
     //OSCCON = 0b01011010;           //Internal Oscillator 1Mhz --- SL900A -> 1.5v
     //OSCCON = 0b01101010;           //Internal Oscillator 4Mhz
     OSCCON = 0b01110010;         //Internal Oscillator 8Mhz
     //OSCCON = 0b01111010;         //Internal Oscillator 16Mhz
     TRISC.B1 = 0;          //RC1 output Select SPI
     PORTC.B1 = 1;
     TRISB.B4 = 0;          //RB4 output test led
    
     //SPI
     SPI1_Init_Advanced(_SPI_MASTER_OSC_DIV4, _SPI_DATA_SAMPLE_MIDDLE, _SPI_CLK_IDLE_LOW, _SPI_LOW_2_HIGH);
     //SPI1_Init();
     //Choose MODE in here
uiMo = WRITE;
     //uiAdd = 0x047E;      //the last physical address of SL900A User_Memory
     uiAdd    = 0;      //The first physical address of SL900A User_Memory
     ucwrData = 0x01;
     
     for (i=0;i<100;i++){
             SL900A_Write(uiMo,uiAdd+i,ucwrData);
             delay_ms(1);
        }
     while(1){
        PORTB.B4 = 0;
        //delay_ms(100);
        //PORTB.B4 = 0;
        //delay_ms(100);
     }
}