Steven Blair / Mbed 2 deprecated rapid61850-SV-LE

An mbed implementation of IEC 61850-9-2LE Sample Values. Creating using the rapid61850 library, available at: https://github.com/stevenblair/rapid61850.

Dependencies:   mbed

An mbed implementation of IEC 61850-9-2LE Sample Values. Creating using the rapid61850 library, available at: https://github.com/stevenblair/rapid61850.

rapid61850/decodePacket.c@0:f09b7bb8bcce, 2012-10-02 (annotated)

Committer:
sblair
Date:
Tue Oct 02 21:31:05 2012 +0000
Revision:
0:f09b7bb8bcce
converted library to folder

Who changed what in which revision?

UserRevisionLine numberNew contents of line
sblair 0:f09b7bb8bcce 1 /**
sblair 0:f09b7bb8bcce 2 * Rapid-prototyping protection schemes with IEC 61850
sblair 0:f09b7bb8bcce 3 *
sblair 0:f09b7bb8bcce 4 * Copyright (c) 2012 Steven Blair
sblair 0:f09b7bb8bcce 5 *
sblair 0:f09b7bb8bcce 6 * This program is free software; you can redistribute it and/or
sblair 0:f09b7bb8bcce 7 * modify it under the terms of the GNU General Public License
sblair 0:f09b7bb8bcce 8 * as published by the Free Software Foundation; either version 2
sblair 0:f09b7bb8bcce 9 * of the License, or (at your option) any later version.
sblair 0:f09b7bb8bcce 10
sblair 0:f09b7bb8bcce 11 * This program is distributed in the hope that it will be useful,
sblair 0:f09b7bb8bcce 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
sblair 0:f09b7bb8bcce 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
sblair 0:f09b7bb8bcce 14 * GNU General Public License for more details.
sblair 0:f09b7bb8bcce 15
sblair 0:f09b7bb8bcce 16 * You should have received a copy of the GNU General Public License
sblair 0:f09b7bb8bcce 17 * along with this program; if not, write to the Free Software
sblair 0:f09b7bb8bcce 18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
sblair 0:f09b7bb8bcce 19 */
sblair 0:f09b7bb8bcce 20
sblair 0:f09b7bb8bcce 21 #include "decodePacket.h"
sblair 0:f09b7bb8bcce 22 //#include "svEncodeBasic.h"
sblair 0:f09b7bb8bcce 23
sblair 0:f09b7bb8bcce 24
sblair 0:f09b7bb8bcce 25 // returns size of length field, from first byte
sblair 0:f09b7bb8bcce 26 int getLengthFieldSize(unsigned char byte) {
sblair 0:f09b7bb8bcce 27 if (byte <= 126) {
sblair 0:f09b7bb8bcce 28 return 1;
sblair 0:f09b7bb8bcce 29 }
sblair 0:f09b7bb8bcce 30 else {
sblair 0:f09b7bb8bcce 31 return 1 + (byte & 0x7F);
sblair 0:f09b7bb8bcce 32 }
sblair 0:f09b7bb8bcce 33 }
sblair 0:f09b7bb8bcce 34
sblair 0:f09b7bb8bcce 35 //TODO check this works for all inputs, e.g., buf[1] = 0xFF
sblair 0:f09b7bb8bcce 36 int decodeLength(unsigned char *buf) {
sblair 0:f09b7bb8bcce 37 if (buf[0] <= 126) {
sblair 0:f09b7bb8bcce 38 return buf[0];
sblair 0:f09b7bb8bcce 39 }
sblair 0:f09b7bb8bcce 40 else {
sblair 0:f09b7bb8bcce 41 int bytes = (buf[0] & 0x7F);
sblair 0:f09b7bb8bcce 42
sblair 0:f09b7bb8bcce 43 if (bytes == 1) {
sblair 0:f09b7bb8bcce 44 return buf[1];
sblair 0:f09b7bb8bcce 45 }
sblair 0:f09b7bb8bcce 46 else if (bytes == 2) { // assumes max length of 2^15
sblair 0:f09b7bb8bcce 47 return ((buf[1] & 0xFF) << 8) | (buf[2] & 0xFF);
sblair 0:f09b7bb8bcce 48 }
sblair 0:f09b7bb8bcce 49 }
sblair 0:f09b7bb8bcce 50
sblair 0:f09b7bb8bcce 51 return 0;
sblair 0:f09b7bb8bcce 52 }