Added documenation for enableDisable flag

See comment in writeRead for explanation.

src/turboPmacAxis.cpp

@@ -15,6 +15,14 @@
 
 struct turboPmacAxisImpl {
     bool waitForHandshake;
+    /*
+    This flag is set to true, if the controller is currently enabling /
+    disabling the motor and false otherwise. This flag is used in the doPoll
+    method to check if the enableRBV PV should be set or not in order to prevent
+    a premature change of state (controller reports that the motor is already
+    enabled / disabled while it is not ready yet to receive new commands).
+    */
+    bool enableDisable;
     time_t timeAtHandshake;
     // The axis status is used when enabling / disabling the motor
     int axisStatus;
@@ -64,6 +72,7 @@ turboPmacAxis::turboPmacAxis(turboPmacController *pC, int axisNo,
 
     pTurboPmacA_ = std::make_unique<turboPmacAxisImpl>(
         (turboPmacAxisImpl){.waitForHandshake = false,
+                            .enableDisable = false,
                             .timeAtHandshake = 0,
                             .axisStatus = 0,
                             .needInit = false});
@@ -253,9 +262,6 @@ asynStatus turboPmacAxis::doPoll(bool *moving) {
     double lowLimit = 0.0;
     double limitsOffset = 0.0;
 
-    // Was the axis idle during the previous poll?
-    int previousStatusDone = 1;
-
     // =========================================================================
 
     if (pTurboPmacA_->needInit) {
@@ -332,8 +338,6 @@ asynStatus turboPmacAxis::doPoll(bool *moving) {
         return status;
     }
 
-    getAxisParamChecked(this, motorStatusDone, &previousStatusDone);
-
     // Query the axis status
     snprintf(command, sizeof(command),
              "P%2.2d00 Q%2.2d10 P%2.2d01 Q%2.2d13 Q%2.2d14", axisNo_, axisNo_,
@@ -369,9 +373,12 @@ asynStatus turboPmacAxis::doPoll(bool *moving) {
     // Store the axis status
     pTurboPmacA_->axisStatus = axStatus;
 
-    // Update the enablement PV
+    // Update the enablement PV, if we are not in the middle of a enabling /
-    setAxisParamChecked(this, motorEnableRBV,
+    // disabling procedure.
-                        (axStatus != -3 && axStatus != -5));
+    if (!(pTurboPmacA_->enableDisable)) {
+        setAxisParamChecked(this, motorEnableRBV,
+                            (axStatus != -3 && axStatus != -5));
+    }
 
     // Create the unique callsite identifier manually so it can be used later in
     // the shouldBePrinted calls.
@@ -833,7 +840,6 @@ asynStatus turboPmacAxis::doMove(double position, int relative,
 
 asynStatus turboPmacAxis::stop(double acceleration) {
 
-    // Status of read-write-operations of ASCII commands to the controller
     asynStatus status = asynSuccess;
 
     char command[pC_->MAXBUF_] = {0};
@@ -857,6 +863,18 @@ asynStatus turboPmacAxis::stop(double acceleration) {
     // if we're currently inside it.
     pTurboPmacA_->waitForHandshake = false;
 
+    /*
+    Stopping the motor results in a movement and further move commands have to
+    wait until the stopping movement is done. Therefore, we need to wait until
+    the poller "sees" the changed state (otherwise, we risk issuing move
+    commands while the motor is stopping). To ensure that at least one poll is
+    done, this thread (which also runs move commands) is paused for twice the
+    idle poll period.
+    */
+    unsigned int idlePollMicros =
+        (unsigned int)ceil(pC_->idlePollPeriod() * 1e6);
+    usleep(2 * idlePollMicros);
+
     return status;
 }
 
@@ -886,14 +904,8 @@ asynStatus turboPmacAxis::doReset() {
     // if we're currently inside it.
     pTurboPmacA_->waitForHandshake = false;
 
-    // Disable the axis, if it is not in a moving state
+    // Disable the axis
-    int axStat = pTurboPmacA_->axisStatus;
+    return enable(false);
-    if (axStat == 0 || axStat == -6) {
-        snprintf(command, sizeof(command), "M%2.2d14=0", axisNo_);
-        status = pC_->writeRead(axisNo_, command, response, 0);
-    }
-
-    return status;
 }
 
 /*
@@ -1052,7 +1064,7 @@ asynStatus turboPmacAxis::rereadEncoder() {
 
 asynStatus turboPmacAxis::enable(bool on) {
 
-    int timeout_enable_disable = 2;
+    int timeout_enable_disable = 5;
     char command[pC_->MAXBUF_] = {0};
     char response[pC_->MAXBUF_] = {0};
     int nvals = 0;
@@ -1080,13 +1092,16 @@ asynStatus turboPmacAxis::enable(bool on) {
         axStatus == 5 || axStatus == 6 || axStatus == 7 || axStatus == 8 ||
         axStatus == 9 || axStatus == 10 || axStatus == 11 || axStatus == 12 ||
         axStatus == 13 || axStatus == 15 || axStatus == 16) {
-        asynPrint(pC_->pasynUser(), ASYN_TRACE_ERROR,
+
-                  "Controller \"%s\", axis %d  => %s, line %d\nAxis is not "
+        asynPrint(
-                  "idle and can therefore not be enabled / disabled.\n",
+            pC_->pasynUser(), ASYN_TRACE_ERROR,
-                  pC_->portName, axisNo_, __PRETTY_FUNCTION__, __LINE__);
+            "Controller \"%s\", axis %d  => %s, line %d\nAxis is not "
+            "idle (status %d) and can therefore not be enabled / disabled.\n",
+            pC_->portName, axisNo_, __PRETTY_FUNCTION__, __LINE__, axStatus);
 
         setAxisParamChecked(this, motorMessageText,
                             "Axis cannot be disabled while it is moving.");
+        pTurboPmacA_->enableDisable = false;
         return asynError;
     }
 
@@ -1109,7 +1124,10 @@ asynStatus turboPmacAxis::enable(bool on) {
         }
     }
 
-    // Enable / disable the axis if it is not moving
+    // Now the actual enabling / disabling starts
+    pTurboPmacA_->enableDisable = true;
+
+    // Enable / disable the axis
     snprintf(command, sizeof(command), "M%2.2d14=%d", axisNo_, on);
     asynPrint(pC_->pasynUser(), ASYN_TRACE_FLOW,
               "Controller \"%s\", axis %d  => %s, line %d\n%s axis\n",
@@ -1127,10 +1145,14 @@ asynStatus turboPmacAxis::enable(bool on) {
     int startTime = time(NULL);
     while (time(NULL) < startTime + timeout_enable_disable) {
 
+        // Wait a bit between status updates from the controller.
+        usleep(10000);
+
         // Read the axis status
-        usleep(100000);
         status = pC_->writeRead(axisNo_, command, response, 1);
         if (status != asynSuccess) {
+            // Enabling / disabling procedure failed
+            pTurboPmacA_->enableDisable = false;
             return status;
         }
         nvals = sscanf(response, "%d", &pTurboPmacA_->axisStatus);
@@ -1140,9 +1162,13 @@ asynStatus turboPmacAxis::enable(bool on) {
         }
 
         if ((pTurboPmacA_->axisStatus != -3) == on) {
+            usleep(500000);
+
             bool moving = false;
-            // Perform a poll to update the parameter library
+            forcedPoll(&moving);
-            poll(&moving);
+
+            // Enabling / disabling procedure is completed (successfully)
+            pTurboPmacA_->enableDisable = false;
             return asynSuccess;
         }
     }
@@ -1159,6 +1185,9 @@ asynStatus turboPmacAxis::enable(bool on) {
     snprintf(command, sizeof(command), "Failed to %s within %d seconds",
              on ? "enable" : "disable", timeout_enable_disable);
     setAxisParamChecked(this, motorMessageText, command);
+
+    // Enabling / disabling procedure failed
+    pTurboPmacA_->enableDisable = false;
     return asynError;
 }
 

src/turboPmacController.cpp

@@ -207,7 +207,6 @@ asynStatus turboPmacController::writeRead(int axisNo, const char *command,
     // Definition of local variables.
     asynStatus status = asynSuccess;
     asynStatus timeoutStatus = asynSuccess;
-    // char fullCommand[MAXBUF_] = {0};
     char drvMessageText[MAXBUF_] = {0};
     char modResponse[MAXBUF_] = {0};
     int motorStatusProblem = 0;
@@ -255,6 +254,10 @@ asynStatus turboPmacController::writeRead(int axisNo, const char *command,
         pasynOctetSyncIOipPort(), command, commandLength, response, MAXBUF_,
         pTurboPmacC_->comTimeout, &nbytesOut, &nbytesIn, &eomReason);
 
+    // if (strchr(command, '=')) {
+    //     usleep(20000);
+    // }
+
     msgPrintControlKey comKey =
         msgPrintControlKey(portName, axisNo, __PRETTY_FUNCTION__, __LINE__);