Steven Blair
The goal of this software is to automatically generate C/C++ code which reads and writes GOOSE and Sampled Value packets. Any valid IEC 61850 Substation Configuration Description (SCD) file, describing GOOSE and/or SV communications, can be used as the input. The output code is lightweight and platform-independent, so it can run on a variety of devices, including low-cost microcontrollers. It\'s ideal for rapid-prototyping new protection and control systems that require communications. This mbed project is a simple example of this functionality. Other code: https://github.com/stevenblair/rapid61850 Project homepage: http://personal.strath.ac.uk/steven.m.blair/
Diff: svDecodePacket.c
- Revision:
- 0:230c10b228ea
- Child:
- 1:9399d44c2b1a
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/svDecodePacket.c Fri Oct 07 13:41:08 2011 +0000
@@ -0,0 +1,99 @@
+#include "svDecodeBasic.h"
+#include "ied.h"
+#include "svDecode.h"
+#include "svPacketData.h"
+#include "decodePacket.h"
+#include <stddef.h>
+
+
+void svDecodeASDU(unsigned char *buf, int len, int noASDU) {
+ unsigned char tag; // assumes only one byte is used
+ int lengthFieldSize;
+ int lengthValue;
+ int offsetForNonSequence;
+ unsigned char *svID = NULL;
+ int svIDLength = 0;
+
+ int i = 0;
+ for (i = 0; i < len;) {
+ tag = (unsigned char) buf[i];
+ lengthFieldSize = getLengthFieldSize((unsigned char) buf[i + 1]);
+ lengthValue = decodeLength((unsigned char *) &buf[i + 1]);
+ offsetForNonSequence = 1 + lengthFieldSize + lengthValue;
+
+ //printf("\ttag: %x, noASDU: %u, lengthFieldSize: %i, lengthValue: %i, offset: %i\n", tag, noASDU, lengthFieldSize, lengthValue, offsetForNonSequence);
+
+ switch (tag) {
+ case 0x80:
+ svID = &buf[i + 1 + lengthFieldSize];
+ svIDLength = lengthValue;
+ break;
+ case 0x81:
+
+ break;
+ case 0x82:
+ // TODO: may be useful to store smpCnt value
+ break;
+ case 0x83:
+
+ break;
+ case 0x84:
+
+ break;
+ case 0x85:
+
+ break;
+ case 0x86:
+
+ break;
+ case 0x87:
+ if (svID != NULL) {
+ svDecodeDataset(&buf[i + 1 + lengthFieldSize], lengthValue, noASDU, svID, svIDLength);
+ }
+ break;
+ default:
+ break;
+ }
+
+ i += offsetForNonSequence;
+ }
+}
+
+void svDecodeAPDU(unsigned char *buf, int len) {
+ unsigned char tag = (unsigned char) buf[0]; // assumes only one byte is used
+ int lengthFieldSize = getLengthFieldSize((unsigned char) buf[1]);
+ int lengthValue = decodeLength((unsigned char *) &buf[1]);
+ int offsetForSequence = 1 + lengthFieldSize;
+ int offsetForNonSequence = 1 + lengthFieldSize + lengthValue;
+ //static unsigned int noASDU = 0;
+ static unsigned int ASDU = 0;
+
+ //printf("tag: %x, noASDU: %u, lengthFieldSize: %i, lengthValue: %i, offset: %i\n", tag, noASDU, lengthFieldSize, lengthValue, offsetForNonSequence);
+
+ switch (tag) {
+ case 0x60:
+ svDecodeAPDU(&buf[offsetForSequence], lengthValue);
+ break;
+ case 0x80:
+ //noASDU = (unsigned int) buf[1 + lengthFieldSize]; // assuming noASDU is < 126
+ ASDU = 0;
+ svDecodeAPDU(&buf[offsetForNonSequence], len - offsetForNonSequence);
+ break;
+ case 0xA2:
+ svDecodeAPDU(&buf[offsetForSequence], lengthValue);
+ break;
+ case 0x30:
+ svDecodeASDU(&buf[offsetForSequence], lengthValue, ASDU++);
+
+ svDecodeAPDU(&buf[offsetForNonSequence], len - offsetForNonSequence);
+ break;
+ default:
+ break;
+ }
+}
+
+void svDecode(unsigned char *buf, int len) {
+ unsigned short APDULength = ((buf[21] << 8) | buf[22]) - 8; // must use length in PDU because total bytes (len) may contain CRC
+
+ svDecodeAPDU(&buf[26], APDULength); // cuts out frame header (fixed size of 26 bytes before start of APDU)
+}