  }
   
  int XYStage::SetRelativePositionSteps(long x, long y)
-@@ -1020,27 +1027,34 @@
+@@ -1020,27 +1042,40 @@
     command << "GR," << x << "," << y;
  
     // send command

===================================================================
--- DeviceAdapters/Prior/Prior.cpp	(revision 15982)
+++ DeviceAdapters/Prior/Prior.cpp	(working copy)
@@ -984,27 +984,34 @@
    command << "G," << x << "," << y;
 
    // send command

+       {
+           int errNo = atoi(answer.substr(2).c_str());
+           ret = ERR_OFFSET + errNo;
+           SLEEP(SLEEP_TIME);
+           continue;
+       }
+       else {
+           ret = ERR_UNRECOGNIZED_ANSWER;
+       }
+       SLEEP(SLEEP_TIME);
    }
-   else if (answer.substr(0, 1).compare("E") == 0 && answer.length() > 2)
-   {
