Sync Process

aa1c00ab31 18 02 f65c7066 804043000000 2e470100 04000000000000 7f873cf3
                                       ^^^^^^^^
                                       Batch number (little-endian)

import struct

def extract_batch_number(packet_hex):
    """Extract batch number from status packet"""
    packet = bytearray.fromhex(packet_hex)
    # Batch number at bytes 17-20 (little-endian u32)
    batch_num = struct.unpack('<I', packet[17:21])[0]
    return batch_num

def create_batch_request(batch_number, packet_count):
    """Create batch retrieval command"""
    # Command format: aa10005723{count}1701{batch}00000000{checksum}
    header = bytearray.fromhex('aa10005723')
    count = bytes([packet_count])
    cmd_code = bytearray.fromhex('1701')
    batch = struct.pack('<I', batch_number)
    padding = bytearray.fromhex('00000000')
    
    # Assemble command (without checksum)
    cmd = header + count + cmd_code + batch + padding
    
    # Calculate CRC-32 checksum (see Commands section)
    checksum = calculate_crc32(cmd)
    
    return cmd + checksum

# Example usage
status_packet = "aa1c00ab3118 02 f65c7066 804043000000 2e470100 04000000000000 7f873cf3"
batch_num = extract_batch_number(status_packet.replace(' ', ''))
print(f"Batch number: {batch_num}")  # Output: 83758

# Create retrieval command
cmd = create_batch_request(batch_num, packet_count=0x42)
print(f"Command: {cmd.hex()}")