Avoid unnecessary polling if the axis is disconnected.

src/masterMacsAxis.cpp

@@ -425,6 +425,15 @@ asynStatus masterMacsAxis::doPoll(bool *moving) {
         // Perform the rest of the poll, but remember if sth. failed in the
         // init.
         poll_status = init();
+
+        // If the axis is not connected, we don't need to continue with the poll
+        if (poll_status == asynDisconnected) {
+            // moving is uninitialized from asynMotorController, so we need to
+            // make sure it has a reasonable value if the axis is disconnected.
+            // Obviously, we assume that the disconnected axis is not moving.
+            *moving = false;
+            return poll_status;
+        }
     }
 
     // Are we currently waiting for a handshake?

src/masterMacsController.cpp

@@ -340,11 +340,8 @@ asynStatus masterMacsController::writeRead(int axisNo, int tcpCmd,
                  "Connection timeout. Please call the support.");
         break;
     case asynDisconnected:
-        snprintf(drvMessageText, sizeof(drvMessageText),
-                 "Axis is not connected.");
         break;
     case asynDisabled:
-        snprintf(drvMessageText, sizeof(drvMessageText), "Axis is disabled.");
         break;
     case asynError:
         // Do nothing - error message drvMessageText has already been set.
@@ -465,10 +462,9 @@ asynStatus masterMacsController::parseResponse(
 
             break;
         } else if (fullResponse[i] == '\x15') {
-            /*
-            NAK
-            This indicates that the axis is not connected. This is not an error!
-            */
+            // NAK
+            // This indicates that the axis is not connected. This is not an
+            // error!
             snprintf(drvMessageText, MAXBUF_, "Axis not connected.");
 
             // Motor was connected before -> Update the paramLib entry and PV