sungrow/modbus/lrc.go

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2021-01-10 14:43:46 +11:00
// Copyright 2014 Quoc-Viet Nguyen. All rights reserved.
// This software may be modified and distributed under the terms
// of the BSD license. See the LICENSE file for details.
package modbus
// Longitudinal Redundancy Checking
type lrc struct {
sum uint8
}
func (lrc *lrc) reset() *lrc {
lrc.sum = 0
return lrc
}
func (lrc *lrc) pushByte(b byte) *lrc {
lrc.sum += b
return lrc
}
func (lrc *lrc) pushBytes(data []byte) *lrc {
var b byte
for _, b = range data {
lrc.sum += b
}
return lrc
}
func (lrc *lrc) value() byte {
// Return twos complement
return uint8(-int8(lrc.sum))
}