Fix serial I/O error checking

git-svn-id: https://hamlib.svn.sourceforge.net/svnroot/hamlib/trunk@2337 7ae35d74-ebe9-4afe-98af-79ac388436b8

tentec/orion.c

@@ -2,7 +2,7 @@
  *  Hamlib TenTenc backend - TT-565 description
  *  Copyright (c) 2004-2008 by Stephane Fillod & Martin Ewing
  *
- *	$Id: orion.c,v 1.24 2008-02-15 23:04:51 aa6e Exp $
+ *	$Id: orion.c,v 1.25 2008-05-01 21:30:28 aa6e Exp $
  *
  *   This library is free software; you can redistribute it and/or modify
  *   it under the terms of the GNU Library General Public License as
@@ -130,10 +130,10 @@ int tt565_transaction(RIG *rig, const char *cmd, int cmd_len, char *data, int *d
         /* no data expected, TODO: flush input? */    
         if (!data || !data_len) {
                 if (*cmd != '*') {     // i.e. was not a 'write' to rig...
-                    rig_debug(RIG_DEBUG_ERR,"reject 1\n");
-                    return -RIG_ERJCTED;    // bad news!
+                    rig_debug(RIG_DEBUG_ERR,"cmd reject 1\n");
+                    return -RIG_ERJCTED;
                     }
-                return RIG_OK;	/* normal exit if no read */
+                return RIG_OK;	/* normal exit if write, but no read */
                 }
 #ifdef TT565_TIME
 	ft1 = tt565_timenow();
@@ -142,25 +142,27 @@ int tt565_transaction(RIG *rig, const char *cmd, int cmd_len, char *data, int *d
 	*data_len = read_string(&rs->rigport, data, *data_len, 
 		        EOM, strlen(EOM));
 	if (!strncmp(data,"Z!",2)) {     // command unrecognized??
-        rig_debug(RIG_DEBUG_ERR,"reject 2\n");
+        	rig_debug(RIG_DEBUG_ERR,"cmd reject 2\n");
         	return -RIG_ERJCTED;	// what is a better error return?
         	}
-    if (cmd[0] != '?') {              // was this a write to the rig?
-        rig_debug(RIG_DEBUG_ERR,"reject 3\n");
-        return -RIG_ERJCTED;        // terrible, can't get here??
+	/* XX and ?V are oddball commands.  Thanks, Ten-Tec! */
+        if (!strncmp(cmd,"XX",2)) {	// Was it a firmware reset cmd?
+        	return RIG_OK;		// Then we accept the response.
         	}
-    else {                          // no, it was a 'read', phew!
-        if (!strncmp(cmd,"?V",2)) {
-            return RIG_OK;          // special case for ?V command
+        if (!strncmp(cmd,"?V",2)) {	// Was it a read firmware version cmd?
+        	return RIG_OK;		// ditto
         	}
+	if (cmd[0] != '?') {		// was this a read cmd?
+		rig_debug(RIG_DEBUG_ERR,"cmd reject 3\n");
+		return -RIG_ERJCTED;	// No, but it should have been!
+		}
+	else {                          // Yes, it was a 'read', phew!
 	        if (!strncmp(data+1,cmd+1,cmd_len-2)) {  //reponse matches cmd?
 	            return RIG_OK;	// all is well, normal exit
 	            }
-        else {
-            /* The command read back does not match the command that
-                was written.  What to do?  We report the problem if debugging,
-                and issue another read in hopes that
-                will make it sync up right.
+	        else { /* The command read back does not match the command that
+	                was written.  We report the problem if debugging,
+	                and issue another read in hopes of eventual success.
 	                */
 	            rig_debug(RIG_DEBUG_ERR,
 	                "** retry after delay (io=%d, retry=%d) **\n",