Amada CD-A Series, Руководство по эксплуатации

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APPENDIX D: COMMUNICATIONS
CD-A DUAL PULSE RESISTANCE WELDING POWER SUPPLY
D-8 990-430
EXAMPLE #1
An example of sending a TYPE command to the CD-A: <STX>“TY000D”<ETX>
The command: “TY”
The Count is: “00”
The check sum is “0D”. Which is calculated from the ASCII (American Standard code for information
interchange) and is a two charter ASCII HEX string calculated from the sum of all bytes except <stx>,
<cksum>, and <etx>. ‘T’ + ‘Y’ + ‘0’ + ‘0’
Looking up the value for each character, We get 0x54 + 0x59 + 0x30 + 0x30 = 0x10D HEX
In decimal 84 + 89 + 48 + 48 = 269 decimal.
The check sum is a value between 0 and 255; Therefore, 269 – 255*n = 14 decimal = 0D hex.
Where n = (check sum / 255). Here it is only 1.
If the check sum was 9C4 hex = 2500 decimal. Then n = 2500 / 256 = 9.7.
Using only the hole number n = 9
The final check sum is (2500 – (256 * 9)) = 196 decimal or 0xC4 hex
A better way is to take the final check sum and AND it with 255 (0x0FF).
In hex, taking the final check sum 0x9C4 and ANDing it with 0xFF = 0xC4, or in decimal 2500 AND
255 = 196.
EXAMPLE #2
Now we wish to find out how many welds are stored in the CD-A weld buffer.
The total command is: <STX>“TC00F7”<ETX>. “TC” is the command, “00” is the count, and “F7” is
the check sum.
If the CD-A send back: <STX>”TC0600000522”<ETX>, then the command is “TC” (or current weld
counter), the data count is 6 (“06”), and the number of welds stored is 5 (“000005”). The check sum is
22 hex (in decimal 84 + 67 + 48 + 54 + 48 + 48 + 48 + 48 + 48 + 53 = 546.
546 / 256 = 2.13. Therefore the check sum is 546 – (256*2) = 34 decimal or 22 hex.