@tbob wrote:
Once you have the sum of the bytes (a number), AND it with decimal 255, which is the same as FF. These are numbers, not strings. The result is the calculated checksum number. You can use the equals function to compare it to an expected checksum. Wire the calculated checksum in one terminal and the expected checksum in the other (255 in your case) and the output will be true if the two numbers are equal, false if they are not. After converting strings or hex bytes into numbers, you can work with numbers. No need for strings anymore. Whether you want to display the numbers in decimal (255) or hex (FF) makes no difference, the numbers are the same.
I have a similar dilemna. I have a controller that needs me to:
1. take a number
2. remove the decimal
3. convert to hex
4. reverse it and add zeroes to the end if needed
Example:
2134.125 to
2134125 to
2009 6D to
add STX, Address, command #, "data byte" (6D90 2000(h)),ETX
then find checksum......
I tried did all as follows but when I use the "number to hexidecimal string" it obviously gives me a "hex" string. What I need is a hex string in hex format....
6D90 2000 not 6D902000.
Any ideas?
Harene M Pitter
