Problems to controll M0601/FIT1042

Hello,

I have an Arduino UNO R4 WIFI.

Mounted on it is the RS485 Shield v1.0.

Motor: FIT1042 / M0601

Orange -> B
White -> A
Brown -> Ground

The following code is running on the Arduino.
 

#include <Arduino.h>

#define RS485_DIR_PIN 2

// --------------------------------------------------
// SEND FRAME
// --------------------------------------------------
void sendFrame(uint8_t *data, int len)
{
   digitalWrite(RS485_DIR_PIN, HIGH);

   delay(5);

   Serial1.write(data, len);
   Serial1.flush();

   delay(5);

   digitalWrite(RS485_DIR_PIN, LOW);
}

// --------------------------------------------------
// PRINT HEX BYTE
// --------------------------------------------------
void printHex(uint8_t b)
{
   Serial.print("0x");

   if (b < 16)
       Serial.print("0");

   Serial.print(b, HEX);
   Serial.print(" ");
}

// --------------------------------------------------
// READ RESPONSE
// --------------------------------------------------
void readResponse()
{
   unsigned long start = millis();

   while (millis() - start < 300)
   {
       while (Serial1.available())
       {
           uint8_t b = Serial1.read();

           printHex(b);
       }
   }

   Serial.println();
}

// --------------------------------------------------
// SETUP
// --------------------------------------------------
void setup()
{
   pinMode(RS485_DIR_PIN, OUTPUT);

   // Empfangsmodus
   digitalWrite(RS485_DIR_PIN, LOW);

   Serial.begin(115200);
   Serial1.begin(115200);

   delay(3000);

   Serial.println();
   Serial.println("=== M0601 SIMPLE SPEED TEST ===");
}

// --------------------------------------------------
// LOOP
// --------------------------------------------------
void loop()
{
   // -------------------------------------------------
   // Speed Command
   // -------------------------------------------------

   uint8_t frame[10] =
   {
       0x01, // ID
       0x64, // CMD Speed
       0x00,
       0x64, // Speed = 100
       0x00,
       0x00,
       0x00,
       0x00,
       0x00,
       0xC9  // Beispiel Checksum
   };

   // -----------------------------
   // PRINT TX
   // -----------------------------
   Serial.print("TX: ");

   for (int i = 0; i < 10; i++)
   {
       printHex(frame[i]);
   }

   Serial.println();

   // -----------------------------
   // SEND
   // -----------------------------
   sendFrame(frame, 10);

   // -----------------------------
   // PRINT RX
   // -----------------------------
   Serial.print("RX: ");

   readResponse();

   delay(2000);
}

i tried:
- Swapped A and B
- Swapped IO pins 1 and 2
- Swapped the black and brown wires
- Ensured the motor and Arduino share a common ground
- Applied a steady 18-volt supply to the motor
- Verified that the motor exhibits resistance once power is applied
- Tested both a different motor and a different Shield

Can somebody help me plz ?
Is there a libary.h for the motor?

thx