i2c problem with AD5121 digital potentiometer

I use arduino uno

I find the address (0x2F) of the i2c Scanner and a potentiometer is connected correctly, I think.
Code is definitely something wrong because I can’t change the output resistance.

AD5121 coupling

Link AD5121 data sheet:

a code example what works for AD5171 and AD5259.

#include <Wire.h>

void setup()
  Wire.begin(); // join i2c bus (address optional for master)

byte val = 0;
byte add = 47;  //device address #47 (0x2F)

void loop()
  Wire.beginTransmission(add); // transmit to device #47 (0x2F)
  Wire.write(byte(0x00));     // sends instruction byte  
  Wire.write(val);            // sends potentiometer value byte  
  Wire.endTransmission();     // stop transmitting

  val++;        // increment value
  if(val == 64) // if reached 64th position (max)
    val = 0;    // start over from lowest value

Code definitely missing something …
Potentiometer should probably first give some instructions to make it work, or do something, but how?

Wire.write(byte(0x00));     // sends instruction byte


Wire.write(byte(0x10));     // sends instruction byte

Yippee it works! Thank you very much Grumpy_Mike