Checksum crc 16 modbus

[sukbir frwa]

Dear All,
I have a string which I need to get the checksum values via java. Any help on how to achieve this? Thank you.

[James Sabre]

<deleted> since I Googled the title and found a 'modbus' definition.

[sukbir frwa]

Dear All,
Below is what I have found but unfortunately is for CRC32. Can I get something for CRC 16 Modbus.

import java.util.zip.CRC32;
import java.util.zip.Checksum; 
public class chksum 
{ 	
public static void main(String args[]){ 	
	String str = "Generate CRC32 Checksum For Byte Array Example"; 		
		//Convert string to bytes		
		byte bytes[] = str.getBytes(); 		
		Checksum checksum = new CRC16(); 		
		/*		 * To compute the CRC32 checksum for byte array, use		 * 		 * void update(bytes[] b, int start, int length)		 * method of CRC32 class.		 */ 		
		checksum.update(bytes,0,bytes.length); 		
		/*		 * Get the generated checksum using		 * getValue method of CRC32 class.		 */		
		long lngChecksum = checksum.getValue(); 		
		System.out.println("CRC32 checksum for byte array is :" + lngChecksum);	
	} 
}

[sukbir frwa]

Dear James,
I know that I require CRC 16 Modbus but I am not too sure about what polynomial? Can you help me on this? Thank you.

James Sabre wrote:

sukbir sss wrote:Dear All,
I have a string which I need to get the checksum values via java. Any help on how to achieve this? Thank you.

There are many many checksums. You will have to say which checksum you require and what polynomial it should use in the feedback.