Controlling a Giant LED Dot Matrix Sign through RS-485

I ramped my code a little bit, now I wait for serial activity to go away before writing anything, when the sign boots up, I get this message

0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 E0 0 0 0 0 0 FE 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 4 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 10 0 0 0 0 0 0 0 0 8 0 0 0 0 0 0 0 0 C 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 80 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

But it doesn't give any response to messages that I send to it

#define SerialTxControl 3   //RS485 Direction control

#define RS485Transmit    HIGH
#define RS485Receive     LOW

#define Pin13LED         13
const int MSGL = 13;
const int MSGL2 = 6;
byte Byte[MSGL];
byte Trigger[MSGL2];
unsigned long Timer = 0;


void setup()   /****** SETUP: RUNS ONCE ******/
{

 
Byte[0] = 195;
Byte[1] = 255;
Byte[2] = 245;
Byte[3] = 8; //Bytes of data sent
Byte[4] = 'M';
Byte[5] = 0; // Sign Number 0 will brodcast to all
Byte[6] = 1; // 
Byte[7] = 0; // Horizontal position
Byte[8] = 'G';
Byte[9] = 'D';
Byte[10] = 'F';
Byte[11] = 'W';

Trigger[0] = 195;
Trigger[1] = 255;
Trigger[2] = 245;
Trigger[3] = 1; //Byte Counts of Following Data
Trigger[4] = 'T';// Message Type


  // Start the built-in serial port, probably to Serial Monitor
  Serial.begin(9600);
  Serial1.begin(9600);
  pinMode(Pin13LED, OUTPUT);   
  pinMode(SerialTxControl, OUTPUT);    
  
  digitalWrite(SerialTxControl, RS485Transmit);  // Init Transceiver   
  
}//--(end setup )---


void loop()   /****** LOOP: RUNS CONSTANTLY ******/
{
  digitalWrite(SerialTxControl, RS485Receive);
  if(Serial1.available() > 0) {
    Timer = millis();
  }
  if (millis() - Timer > 5000) {
    TransmitMessage();
    Timer = millis();
  }
  
  
  ReadSerial2();

 


 
 
}//--(end main loop )---
void ReadSerial2() {
  digitalWrite(SerialTxControl, RS485Receive);  // Init Transceiver   

    // Declarations
   unsigned char sBuffer[100];
  // digitalWrite(RSE, HIGH);

    // Check for RS485 data
   int nBytes = Serial1.available();
   if(nBytes > 0)
   {
       int nCount = Serial1.readBytes(sBuffer, nBytes);
       for(int nIndex = 0; nIndex < nCount; nIndex++)
       {
           Serial.print(sBuffer[nIndex], HEX);
           Serial.print(" ");
       }// end for
   } //end if
}// end loop

void TransmitMessage(){
  
 digitalWrite(SerialTxControl, RS485Transmit);  // Init Transceiver   
  
  byte chk = 0;
for ( int i=0; i<(MSGL-1); i++)  { //length = 19 (22-02 = 20 - 1)
    chk += Byte[i];    
}
Byte[12] = chk;

//sum=10+C1+00+00+00+3E+90+32+00+21+16+10+1E+11+01+33+C1+0A+CD+19 = 042C
//discard accumulated carries; we get 2C = 0010 1100
//take 2's complemet code : 1101 0011 + 1 = D4 
Serial.println("WriteM");
for ( int i=0; i<MSGL; i++)  { //length = 19 (22-02 = 20 - 1)
    Serial1.write(Byte[i]);
    Serial.println(Byte[i]);
}

chk = 0;
for ( int i=0; i<(MSGL2-1); i++)  { //length = 19 (22-02 = 20 - 1)
    chk += Byte[i];    
}
Trigger[5] = chk;

Serial.println("WriteT");
for ( int i=0; i<MSGL2; i++)  { //length = 19 (22-02 = 20 - 1)
    Serial1.write(Trigger[i]);
    Serial.println(Trigger[i]);
}
}
[code/]

The manual says that the communications uses serial ASCII, and I'm still trying to figure out if I should be using serial.print or serial.write to get that format.