Craftsman G10-0R7G-2SB Manual page 142

8.6.3.1 Byte bit check
Users can choose different bit verification methods as needed, or they can choose no
parity, which will affect the parity bit setting of each byte.
The meaning of even parity: an even parity bit is added before data transmission to
indicate whether the number of "1" in the transmitted data is odd or even. When it is even,
the check position is "0", otherwise it is set. It is "1" to keep the parity of the data
unchanged.
The meaning of odd parity: an odd parity bit is added before data transmission to
indicate whether the number of "1" in the transmitted data is odd or even. When it is odd,
the check position is "0", otherwise it is set. It is "1" to keep the parity of the data
unchanged.
For example, you need to transfer "11001110", the data contains 5 "1", if you use
even parity, its even parity bit is "1", if you use odd parity, its odd parity bit is "0",
transmission In the case of data, the parity bit is calculated at the position of the check bit
of the frame, and the receiving device also performs parity check. If the parity of the
accepted data is found to be inconsistent with the preset, it is considered that the
communication has an error.
8.6.3.2 CRC check method:
Using the RTU frame format, the frame includes a frame error detection field
calculated based on the CRC method. The CRC field detects the contents of the entire
frame. The CRC field is two bytes and contains a 16-bit binary value. It is calculated by
the transmission device and added to the frame. The receiving device recalculates the
CRC of the received frame and compares it with the value in the received CRC field. If the
two CRC values ​ ​ a re not equal, the transmission has an error.
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