libaitcrc/src/pelco.c - diff

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-version 1.1, 2010/01/20 00:06:36
+version 1.2, 2010/01/20 00:15:06
- Line 0
+ Line 1
+ /*************************************************************************
+ * (C) 2010 AITNET ltd - Sofia/Bulgaria - <misho@aitbg.com>
+ *  by Michael Pounov <misho@openbsd-bg.org>
+ *
+ * $Author$
+ * $Id$
+ *
+ *************************************************************************/
+ #include "global.h"
+ /*
+  * crcPelco() Calculate Pelco D/P CRC
+  * @ver = Pelco protocol version (Dd | Pp)
+  * @pkt = Packet for calculate crc
+  * return: crc for packet, if is 0 check and crc_GetErrno() == 1
+         Pelco protocol not supported
+  */
+ inline u_char crcPelco(u_char ver, u_char *pkt)
+ {
+         register u_char i, crc;
+         switch (ver) {
+                 case 'D':
+                 case 'd':
+                         for (i = 1, crc = 0; i < 6; crc += pkt[i++]);
+                         crc %= 0x100;
+                         break;
+                 case 'P':
+                 case 'p':
+                         for (i = 1, crc = pkt[0]; i < 7; crc ^= pkt[i++]);
+                         break;
+                 default:
+                         crc = 0;
+                         crcSetErr(1, "crcAdler(): Invalid parameters!");
+         }
+         return crc;
+ }