Chapter 6 Applied Instructions Symbol D ： Device where the sum is S ： First device stored n ： Number of pieces of data 6_ Explanation 1. Communication protocols use the sum check function to compare checksums on the same data on different occasions or on different representations of the data to verify data integrity. 2. When SM606 is OFF, the instruction uses the 16-bit conversion mode. The instruction adds up n pieces of data in the registers starting from the register specified by S (eight bits as a group). The instruction stores the sum in the register specified by D , and stores the values of the parity bits in D +1. 3. When SM606 is ON, the instruction uses the 8-bit conversion mode.
The instruction adds up the n pieces of data in the registers starting from the register specified by S (eight bits in a group, and only low eight bits are valid). The instruction stores the sum in the register specified by D , and stores the values of the parity bits in D +1. 4. The operand n must be between 1–256. 6-365 API Instruction code Operand Function 1209 CCD P S, D, n Finding the sum check Device X Y M S T C HC D FR SM SR E K 16# “$” F S D n BOOL WORD DWORD LWORD UINT INT DINT LINT REAL LREAL TMR CNT STRING Data type S D n Pulse instruction 16-bit instruction 32-bit instruction ES3 ES3 -