difficulty writing to Indirect Parameters

Issue

I am experiencing some difficulty when using the address in the IPAT table to try and change a variable.

The code block I have attached is able to toggle an LED on and off by changing the value inside a DC source. The code also works for changing the gain of the system. This code block only work when I am pointing it to the direct parameter address. When I change the address to the indirect address listed in the IPAT table it stops working. 

I2C sending function

uint64_t sigsend(u_int16_t addr,u_int16_t param,u_int32_t value) {
    
    //DSP Address
  Wire.beginTransmission(addr); //address high byte

  //Address of parameter
  Wire.write(byte((param >> 8) & 0xff));
  Wire.write(byte((param) & 0xff));
 
  //Data to be written
  Wire.write(byte(value >> 24) &0xff);
  Wire.write(byte(value >> 16) &0xff);
  Wire.write(byte(value >> 8) &0xff);
  Wire.write(value & 0xff);
  
  //End transmission
  Wire.endTransmission();
    return(uint16_t)addr;

Usage in main program
"sigsend(0x38,24585,dec2sig(1));"

my IPAT

If anyone has any experience using the IPAT table your help would be greatly appreciated. 

Best,