Xinje XD Series User Manual

328
C program
Method 2 can simplify the program.
The above C language function is similar to ladder chart of method 1, whose precision is not
high. If it needs to get the high precision, please use float calculation.
Example 2: Calculate CRC parity value via Func Block
CRC calculation rules:
(1)Set 16-bit register (CRC register) = FFFF H
(2)XOR (Exclusive OR) the first 8-bit byte message and the low 16-bit CRC register.
(3)Right shift 1 bit of CRC register, fill 0 into the highest bit.
(4)Check the right shifted value, if it is 0, save the new value from step3 into CRC register; if
it is not 0, XOR the CRC register value with A001 H and then save the result into the CRC
register.
(5)Repeat step3&4 until all the 8-bit have been calculated.
(6) Repeat step(2)~(5), then calculate the next 8-bit message. Until all the messages have been
calculated, the result will be the CRC parity code in CRC register.
Edit C language Function Block program, see graph below:
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Xinje XD Series Specifications

General

Input Voltage	24V DC
Storage Temperature	-20°C to 70°C
Protection Class	IP20
Type	PLC
Series	XD
Programming Language	Ladder Logic, Instruction List
Communication Interface	RS232, RS485
Power Supply	24V DC
Digital Inputs	Available (number varies by model)
Digital Outputs	Available (number varies by model)
Analog Inputs	Available (number varies by model)
Analog Outputs	Available (number varies by model)
Output Type	Relay, Transistor
Number of Inputs	Varies by model (see Digital Inputs and Analog Inputs)
Number of Outputs	Varies by model (see Digital Outputs and Analog Outputs)
Operating Temperature	0°C to 50°C
Humidity	5% to 95% (non-condensing)