diff --git a/tecsdriv.c b/tecsdriv.c
index 1887e14..7c00943 100644
--- a/tecsdriv.c
+++ b/tecsdriv.c
@@ -114,8 +114,11 @@
       self->fTarget = atof(result);
       iRet=CocGet(pMe->pData,"tlimit",result); /* get parameter */
       if (iRet<0) goto Error;
-      fVal = atof(result);
-      iRet = EVCSetPar(self, "upperlimit", fVal,pCon);
+      iRet = EVCGetPar(self, "upperlimit", &fVal);
+      if (abs(fVal - atof(result)) > 1.0e-4 * abs(fVal)) {
+        fVal = atof(result);
+        iRet = EVCSetPar(self, "upperlimit", fVal,pCon);
+      }
       iRet = EVControlWrapper(pCon,pSics,pData,argc,argv);
       if (iRet != 0) {
         iRet=CocGet(pMe->pData,"status",result); /* show status */