Factored out error handling in a dedicated function

This makes it possible to reuse the error handling of the base axis in
derived axis types (e.g. seleneGuide driver).

Makefile

@@ -14,7 +14,7 @@ REQUIRED+=sinqMotor
 motorBase_VERSION=7.2.2
 
 # Specify the version of sinqMotor we want to build against
-sinqMotor_VERSION=0.7.0
+sinqMotor_VERSION=0.11.0
 
 # These headers allow to depend on this library for derived drivers.
 HEADERS += src/turboPmacAxis.h

README.md

@@ -1,5 +1,7 @@
 # turboPmac
 
+## <span style="color:red">Please read the documentation of sinqMotor first: https://git.psi.ch/sinq-epics-modules/sinqmotor</span>
+
 ## Overview
 
 This is a driver for the Turbo PMAC motion controller with the SINQ communication protocol. It is based on the sinqMotor shared library (https://git.psi.ch/sinq-epics-modules/sinqmotor). The header files contain detailed documentation for all public functions. The headers themselves are exported when building the library to allow other drivers to depend on this one.
@@ -17,25 +19,45 @@ The folder "utils" contains utility scripts for working with pmac motor controll
 
 ### Usage in IOC shell
 
-turboPmac exposes the following IOC shell functions (all in turboPmacController.cpp):
+turboPmac exports the following IOC shell functions:
 - `turboPmacController`: Create a new controller object.
 - `turboPmacAxis`: Create a new axis object.
-These functions are parametrized as follows:
+
+The full turboPmacX.cmd file looks like this:
+
 ```
-turboPmacController(
+# Define the name of the controller and the corresponding port
-    "$(NAME)", # Name of the MCU, e.g. mcu1. This parameter should be provided by an environment variable.
+epicsEnvSet("NAME","turboPmacX")
-    "$(ASYN_PORT)", # IP-Port of the MCU. This parameter should be provided by an environment variable.
+epicsEnvSet("ASYN_PORT","p$(NAME)")
-    8, # Maximum number of axes
+
-    0.05, # Busy poll period in seconds
+# Create the TCP/IP socket used to talk with the controller. The socket can be adressed from within the IOC shell via the port name
-    1, # Idle poll period in seconds
+drvAsynIPPortConfigure("$(ASYN_PORT)","172.28.101.24:1025")
-    0.05 # Communication timeout in seconds
+
-    );
+# Create the controller object with the defined name and connect it to the socket via the port name.
-```
+# The other parameters are as follows:
-```
+# 8: Maximum number of axes
-turboPmacAxis(
+# 0.05: Busy poll period in seconds
-    "$(NAME)", # Name of the associated MCU, e.g. mcu1. This parameter should be provided by an environment variable.
+# 1: Idle poll period in seconds
-    1 # Index of the axis.
+# 1: Socket communication timeout in seconds
-    );
+turboPmacController("$(NAME)", "$(ASYN_PORT)", 8, 0.05, 1, 1);
+
+# Define some axes for the specified MCU at the given slot (1, 2 and 5). No slot may be used twice!
+turboPmacAxis("$(NAME)",1);
+turboPmacAxis("$(NAME)",2);
+turboPmacAxis("$(NAME)",5);
+
+# Set the number of subsequent timeouts 
+setMaxSubsequentTimeouts("$(NAME)", 20);
+
+# Configure the timeout frequency watchdog: A maximum of 10 timeouts are allowed in 300 seconds before an alarm message is sent.
+setThresholdComTimeout("$(NAME)", 300, 10);
+
+# Parametrize the EPICS record database with the substitution file named after the MCU.
+epicsEnvSet("SINQDBPATH","$(sinqMotor_DB)/sinqMotor.db")
+dbLoadTemplate("$(TOP)/$(NAME).substitutions", "INSTR=$(INSTR)$(NAME):,CONTROLLER=$(NAME)")
+epicsEnvSet("SINQDBPATH","$(turboPmac_DB)/turboPmac.db")
+dbLoadTemplate("$(TOP)/$(NAME).substitutions", "INSTR=$(INSTR)$(NAME):,CONTROLLER=$(NAME)")
+dbLoadRecords("$(sinqMotor_DB)/asynRecord.db","P=$(INSTR)$(NAME),PORT=$(ASYN_PORT)")
 ```
 
 ### Versioning

src/turboPmacAxis.h

@@ -3,7 +3,7 @@
 #include "sinqAxis.h"
 
 // Forward declaration of the controller class to resolve the cyclic dependency
-// between C804Controller.h and C804Axis.h. See
+// between the controller and the axis .h-file. See
 // https://en.cppreference.com/w/cpp/language/class.
 class turboPmacController;
 
@@ -15,7 +15,8 @@ class turboPmacAxis : public sinqAxis {
      * @param pController         Pointer to the associated controller
      * @param axisNo              Index of the axis
      */
-    turboPmacAxis(turboPmacController *pController, int axisNo);
+    turboPmacAxis(turboPmacController *pController, int axisNo,
+                  bool initialize = true);
 
     /**
      * @brief Destroy the turboPmacAxis
@@ -74,12 +75,20 @@ class turboPmacAxis : public sinqAxis {
      * The following steps are performed:
      * - Read out the motor status, motor position, velocity and acceleration
      * from the MCU and store this information in the parameter library.
-     * - Set the enable PV accordint to the initial status of the axis.
+     * - Set the enable PV according to the initial status of the axis.
      *
      * @return asynStatus
      */
     asynStatus init();
 
+    /**
+     * @brief Implementation of the `doReset` function from sinqAxis.
+     *
+     * @param on
+     * @return asynStatus
+     */
+    asynStatus doReset();
+
     /**
      * @brief Enable / disable the axis.
      *
@@ -103,6 +112,16 @@ class turboPmacAxis : public sinqAxis {
      */
     asynStatus rereadEncoder();
 
+    /**
+     * @brief Interpret the error code and populate the user message accordingly
+     *
+     * @param error
+     * @param userMessage
+     * @param sizeUserMessage
+     * @return asynStatus
+     */
+    asynStatus handleError(int error, char *userMessage, int sizeUserMessage);
+
   protected:
     turboPmacController *pC_;
 
@@ -111,9 +130,6 @@ class turboPmacAxis : public sinqAxis {
 
     // The axis status is used when enabling / disabling the motor
     int axisStatus_;
-
-  private:
-    friend class turboPmacController;
 };
 
 #endif

src/turboPmacController.cpp

@@ -29,23 +29,11 @@ void adjustResponseForPrint(char *dst, const char *src, size_t buf_length) {
     }
 }
 
-/**
- * @brief Construct a new turboPmacController::turboPmacController object
- *
- * @param portName              See documentation of sinqController
- * @param ipPortConfigName      See documentation of sinqController
- * @param numAxes               See documentation of sinqController
- * @param movingPollPeriod      See documentation of sinqController
- * @param idlePollPeriod        See documentation of sinqController
- * @param comTimeout  Time after which a communication timeout error
- * is declared in writeRead (in seconds)
- * @param extraParams           See documentation of sinqController
- */
 turboPmacController::turboPmacController(const char *portName,
                                          const char *ipPortConfigName,
                                          int numAxes, double movingPollPeriod,
                                          double idlePollPeriod,
-                                         double comTimeout)
+                                         double comTimeout, int numExtraParams)
     : sinqController(
           portName, ipPortConfigName, numAxes, movingPollPeriod, idlePollPeriod,
           /*
@@ -53,7 +41,7 @@ turboPmacController::turboPmacController(const char *portName,
           - REREAD_ENCODER_POSITION
           - READ_CONFIG
           */
-          NUM_turboPmac_DRIVER_PARAMS)
+          numExtraParams + NUM_turboPmac_DRIVER_PARAMS)
 
 {
 
@@ -61,27 +49,12 @@ turboPmacController::turboPmacController(const char *portName,
     asynStatus status = asynSuccess;
 
     // Initialization of all member variables
-    lowLevelPortUser_ = nullptr;
     comTimeout_ = comTimeout;
 
     // Maximum allowed number of subsequent timeouts before the user is
     // informed.
     maxSubsequentTimeouts_ = 10;
 
-    // =========================================================================;
-
-    /*
-    We try to connect to the port via the port name provided by the constructor.
-    If this fails, the function is terminated via exit
-    */
-    pasynOctetSyncIO->connect(ipPortConfigName, 0, &lowLevelPortUser_, NULL);
-    if (status != asynSuccess || lowLevelPortUser_ == nullptr) {
-        errlogPrintf("Controller \"%s\" => %s, line %d\nFATAL ERROR "
-                     "(cannot connect to MCU controller).\nTerminating IOC",
-                     portName, __PRETTY_FUNCTION__, __LINE__);
-        exit(-1);
-    }
-
     // =========================================================================
     // Create additional parameter library entries
 
@@ -115,15 +88,15 @@ turboPmacController::turboPmacController(const char *portName,
     const char *message_from_device =
         "\006"; // Hex-code for ACK (acknowledge) -> Each message from the MCU
                 // is terminated by this value
-    status = pasynOctetSyncIO->setInputEos(
+    status = pasynOctetSyncIO->setInputEos(ipPortUser_, message_from_device,
-        lowLevelPortUser_, message_from_device, strlen(message_from_device));
+                                           strlen(message_from_device));
     if (status != asynSuccess) {
         asynPrint(this->pasynUserSelf, ASYN_TRACE_ERROR,
                   "Controller \"%s\" => %s, line %d\nFATAL ERROR "
                   "(setting input EOS failed with %s).\nTerminating IOC",
                   portName, __PRETTY_FUNCTION__, __LINE__,
                   stringifyAsynStatus(status));
-        pasynOctetSyncIO->disconnect(lowLevelPortUser_);
+        pasynOctetSyncIO->disconnect(ipPortUser_);
         exit(-1);
     }
 
@@ -135,7 +108,7 @@ turboPmacController::turboPmacController(const char *portName,
                   "with %s).\nTerminating IOC",
                   portName, __PRETTY_FUNCTION__, __LINE__,
                   stringifyAsynStatus(status));
-        pasynOctetSyncIO->disconnect(lowLevelPortUser_);
+        pasynOctetSyncIO->disconnect(ipPortUser_);
         exit(-1);
     }
 }
@@ -145,39 +118,18 @@ Access one of the axes of the controller via the axis adress stored in asynUser.
 If the axis does not exist or is not a Axis, a nullptr is returned and an
 error is emitted.
 */
-turboPmacAxis *turboPmacController::getAxis(asynUser *pasynUser) {
+turboPmacAxis *turboPmacController::getTurboPmacAxis(asynUser *pasynUser) {
     asynMotorAxis *asynAxis = asynMotorController::getAxis(pasynUser);
-    return turboPmacController::castToAxis(asynAxis);
+    return dynamic_cast<turboPmacAxis *>(asynAxis);
 }
 
 /*
 Access one of the axes of the controller via the axis index.
 If the axis does not exist or is not a Axis, the function must return Null
 */
-turboPmacAxis *turboPmacController::getAxis(int axisNo) {
+turboPmacAxis *turboPmacController::getTurboPmacAxis(int axisNo) {
     asynMotorAxis *asynAxis = asynMotorController::getAxis(axisNo);
-    return turboPmacController::castToAxis(asynAxis);
+    return dynamic_cast<turboPmacAxis *>(asynAxis);
-}
-
-turboPmacAxis *turboPmacController::castToAxis(asynMotorAxis *asynAxis) {
-
-    // =========================================================================
-
-    // If the axis slot of the pAxes_ array is empty, a nullptr must be returned
-    if (asynAxis == nullptr) {
-        return nullptr;
-    }
-
-    // Here, an error is emitted since asyn_axis is not a nullptr but also not
-    // an instance of Axis
-    turboPmacAxis *axis = dynamic_cast<turboPmacAxis *>(asynAxis);
-    if (axis == nullptr) {
-        asynPrint(this->pasynUserSelf, ASYN_TRACE_ERROR,
-                  "Controller \"%s\", axis %d => %s, line %d\nAxis is not "
-                  "an instance of turboPmacAxis",
-                  portName, axis->axisNo_, __PRETTY_FUNCTION__, __LINE__);
-    }
-    return axis;
 }
 
 asynStatus turboPmacController::writeRead(int axisNo, const char *command,
@@ -216,7 +168,7 @@ asynStatus turboPmacController::writeRead(int axisNo, const char *command,
 
     // =========================================================================
 
-    turboPmacAxis *axis = getAxis(axisNo);
+    turboPmacAxis *axis = getTurboPmacAxis(axisNo);
     if (axis == nullptr) {
         // We already did the error logging directly in getAxis
         return asynError;
@@ -273,10 +225,6 @@ asynStatus turboPmacController::writeRead(int axisNo, const char *command,
     // +1 for the carriage return.
     const size_t fullComandLength = offset + commandLength + 1;
 
-    asynPrint(this->pasynUserSelf, ASYN_TRACEIO_DRIVER,
-              "Controller \"%s\", axis %d => %s, line %d\nSending command %s",
-              portName, axisNo, __PRETTY_FUNCTION__, __LINE__, fullCommand);
-
     /*
     We use separated write and read commands here, not the combined writeRead
     method, because the latter is actually a flushWriteRead (see
@@ -291,15 +239,22 @@ asynStatus turboPmacController::writeRead(int axisNo, const char *command,
     trying to reconnect. If the problem persists, ask them to call the support
     */
 
-    status = pasynOctetSyncIO->write(lowLevelPortUser_, fullCommand,
+    status = pasynOctetSyncIO->write(ipPortUser_, fullCommand, fullComandLength,
-                                     fullComandLength, comTimeout_, &nbytesOut);
+                                     comTimeout_, &nbytesOut);
+
+    msgPrintControlKey writeKey =
+        msgPrintControlKey(portName, axisNo, __PRETTY_FUNCTION__, __LINE__);
 
     if (status == asynTimeout) {
 
-        asynPrint(this->pasynUserSelf, ASYN_TRACE_ERROR,
+        if (msgPrintControl_.shouldBePrinted(writeKey, true, pasynUserSelf)) {
+            asynPrint(
+                this->pasynUserSelf, ASYN_TRACE_ERROR,
                 "Controller \"%s\", axis %d => %s, line %d\nTimeout while "
-                  "writing to the MCU\n",
+                "writing to the MCU.%s\n",
-                  portName, axisNo, __PRETTY_FUNCTION__, __LINE__);
+                portName, axisNo, __PRETTY_FUNCTION__, __LINE__,
+                msgPrintControl_.getSuffix());
+        }
 
         timeoutStatus = checkComTimeoutWatchdog(axisNo, drvMessageText,
                                                 sizeof(drvMessageText));
@@ -309,7 +264,7 @@ asynStatus turboPmacController::writeRead(int axisNo, const char *command,
             checkMaxSubsequentTimeouts(timeoutCounter, axis);
             timeoutCounter += 1;
 
-            status = pasynOctetSyncIO->write(lowLevelPortUser_, fullCommand,
+            status = pasynOctetSyncIO->write(ipPortUser_, fullCommand,
                                              fullComandLength, comTimeout_,
                                              &nbytesOut);
             if (status != asynTimeout) {
@@ -321,23 +276,35 @@ asynStatus turboPmacController::writeRead(int axisNo, const char *command,
             }
         }
     } else if (status != asynSuccess) {
-        asynPrint(this->pasynUserSelf, ASYN_TRACE_ERROR,
+        if (msgPrintControl_.shouldBePrinted(writeKey, true, pasynUserSelf)) {
+            asynPrint(
+                this->pasynUserSelf, ASYN_TRACE_ERROR,
                 "Controller \"%s\", axis %d => %s, line %d\nError %s while "
-                  "writing to the controller\n",
+                "writing to the controller.%s\n",
                 portName, axisNo, __PRETTY_FUNCTION__, __LINE__,
-                  stringifyAsynStatus(status));
+                stringifyAsynStatus(status), msgPrintControl_.getSuffix());
+        }
+    } else {
+        msgPrintControl_.resetCount(writeKey, pasynUserSelf);
     }
 
     // Read the response from the MCU buffer
-    status = pasynOctetSyncIO->read(lowLevelPortUser_, response, MAXBUF_,
+    status = pasynOctetSyncIO->read(ipPortUser_, response, MAXBUF_, comTimeout_,
-                                    comTimeout_, &nbytesIn, &eomReason);
+                                    &nbytesIn, &eomReason);
+
+    msgPrintControlKey readKey =
+        msgPrintControlKey(portName, axisNo, __PRETTY_FUNCTION__, __LINE__);
 
     if (status == asynTimeout) {
 
-        asynPrint(this->pasynUserSelf, ASYN_TRACE_ERROR,
+        if (msgPrintControl_.shouldBePrinted(readKey, true, pasynUserSelf)) {
+            asynPrint(
+                this->pasynUserSelf, ASYN_TRACE_ERROR,
                 "Controller \"%s\", axis %d => %s, line %d\nTimeout while "
-                  "reading from the MCU\n",
+                "reading from the MCU.%s\n",
-                  portName, axisNo, __PRETTY_FUNCTION__, __LINE__);
+                portName, axisNo, __PRETTY_FUNCTION__, __LINE__,
+                msgPrintControl_.getSuffix());
+        }
 
         // Add this event to the back of the timeout event counter
         timeoutStatus = checkComTimeoutWatchdog(axisNo, drvMessageText,
@@ -348,8 +315,7 @@ asynStatus turboPmacController::writeRead(int axisNo, const char *command,
             checkMaxSubsequentTimeouts(timeoutCounter, axis);
             timeoutCounter += 1;
 
-            status =
+            status = pasynOctetSyncIO->read(ipPortUser_, response, MAXBUF_,
-                pasynOctetSyncIO->read(lowLevelPortUser_, response, MAXBUF_,
                                             comTimeout_, &nbytesIn, &eomReason);
             if (status != asynTimeout) {
                 asynPrint(this->pasynUserSelf, ASYN_TRACE_ERROR,
@@ -360,11 +326,16 @@ asynStatus turboPmacController::writeRead(int axisNo, const char *command,
             }
         }
     } else if (status != asynSuccess) {
-        asynPrint(this->pasynUserSelf, ASYN_TRACE_ERROR,
+        if (msgPrintControl_.shouldBePrinted(readKey, true, pasynUserSelf)) {
+            asynPrint(
+                this->pasynUserSelf, ASYN_TRACE_ERROR,
                 "Controller \"%s\", axis %d => %s, line %d\nError %s while "
-                  "reading from the controller\n",
+                "reading from the controller.%s\n",
                 portName, axisNo, __PRETTY_FUNCTION__, __LINE__,
-                  stringifyAsynStatus(status));
+                stringifyAsynStatus(status), msgPrintControl_.getSuffix());
+        }
+    } else {
+        msgPrintControl_.resetCount(readKey, pasynUserSelf);
     }
 
     if (timeoutStatus == asynError) {
@@ -372,6 +343,8 @@ asynStatus turboPmacController::writeRead(int axisNo, const char *command,
     }
 
     // The message should only ever terminate due to reason 2
+    msgPrintControlKey terminateKey =
+        msgPrintControlKey(portName, axisNo, __PRETTY_FUNCTION__, __LINE__);
     if (eomReason != 2) {
         status = asynError;
 
@@ -379,10 +352,16 @@ asynStatus turboPmacController::writeRead(int axisNo, const char *command,
                  "Terminated message due to reason %d (should be 2).",
                  eomReason);
 
-        asynPrint(this->pasynUserSelf, ASYN_TRACEIO_DRIVER,
+        if (msgPrintControl_.shouldBePrinted(terminateKey, true,
+                                             pasynUserSelf)) {
+            asynPrint(this->pasynUserSelf, ASYN_TRACE_ERROR,
                       "Controller \"%s\", axis %d => %s, line %d\nMessage "
-                  "terminated due to reason %i\n",
+                      "terminated due to reason %i.%s\n",
-                  portName, axisNo, __PRETTY_FUNCTION__, __LINE__, eomReason);
+                      portName, axisNo, __PRETTY_FUNCTION__, __LINE__,
+                      eomReason, msgPrintControl_.getSuffix());
+        }
+    } else {
+        msgPrintControl_.resetCount(terminateKey, pasynUserSelf);
     }
 
     /*
@@ -394,20 +373,30 @@ asynStatus turboPmacController::writeRead(int axisNo, const char *command,
             numReceivedResponses++;
         }
     }
+    msgPrintControlKey numResponsesKey =
+        msgPrintControlKey(portName, axisNo, __PRETTY_FUNCTION__, __LINE__);
     if (numExpectedResponses != numReceivedResponses) {
         adjustResponseForPrint(modResponse, response, MAXBUF_);
-        asynPrint(this->pasynUserSelf, ASYN_TRACE_ERROR,
+
+        if (msgPrintControl_.shouldBePrinted(numResponsesKey, true,
+                                             pasynUserSelf)) {
+            asynPrint(
+                this->pasynUserSelf, ASYN_TRACE_ERROR,
                 "Controller \"%s\", axis %d => %s, line %d\nUnexpected "
                 "response '%s' (carriage returns are replaced with spaces) "
-                  "for command %s\n",
+                "for command %s.%s\n",
                 portName, axisNo, __PRETTY_FUNCTION__, __LINE__, modResponse,
-                  command);
+                command, msgPrintControl_.getSuffix());
+        }
+
         snprintf(drvMessageText, sizeof(drvMessageText),
                  "Received unexpected response '%s' (carriage returns "
                  "are replaced with spaces) for command %s. "
                  "Please call the support",
                  modResponse, command);
         status = asynError;
+    } else {
+        msgPrintControl_.resetCount(numResponsesKey, pasynUserSelf);
     }
 
     // Create custom error messages for different failure modes, if no error
@@ -437,23 +426,12 @@ asynStatus turboPmacController::writeRead(int axisNo, const char *command,
 
     // Log the overall status (communication successfull or not)
     if (status == asynSuccess) {
-
-        asynPrint(lowLevelPortUser_, ASYN_TRACEIO_DRIVER,
-                  "Controller \"%s\", axis %d => %s, line %d\nDevice "
-                  "response: %s (carriage returns are replaced with spaces)\n",
-                  portName, axisNo, __PRETTY_FUNCTION__, __LINE__, modResponse);
         paramLibStatus = axis->setIntegerParam(this->motorStatusCommsError_, 0);
     } else {
-        asynPrint(lowLevelPortUser_, ASYN_TRACE_ERROR,
+        // Check if the axis already is in an error communication mode. If
-                  "Controller \"%s\", axis %d => %s, line %d\nCommunication "
+        // it is not, upstream the error. This is done to avoid "flooding"
-                  "failed for command %s (%s)\n",
+        // the user with different error messages if more than one error
-                  portName, axisNo, __PRETTY_FUNCTION__, __LINE__, fullCommand,
+        // ocurred before an error-free communication
-                  stringifyAsynStatus(status));
-
-        // Check if the axis already is in an error communication mode. If it is
-        // not, upstream the error. This is done to avoid "flooding" the user
-        // with different error messages if more than one error ocurred before
-        // an error-free communication
         paramLibStatus =
             getIntegerParam(axisNo, motorStatusProblem_, &motorStatusProblem);
         if (paramLibStatus != asynSuccess) {
@@ -494,11 +472,7 @@ asynStatus turboPmacController::writeInt32(asynUser *pasynUser,
 
     // =====================================================================
 
-    turboPmacAxis *axis = getAxis(pasynUser);
+    turboPmacAxis *axis = getTurboPmacAxis(pasynUser);
-    if (axis == nullptr) {
-        // We already did the error logging directly in getAxis
-        return asynError;
-    }
 
     // Handle custom PVs
     if (function == rereadEncoderPosition_) {
@@ -510,22 +484,14 @@ asynStatus turboPmacController::writeInt32(asynUser *pasynUser,
     }
 }
 
-asynStatus sinqController::readInt32(asynUser *pasynUser, epicsInt32 *value) {
+asynStatus turboPmacController::couldNotParseResponse(const char *command,
-    // PMACs can be disabled
+                                                      const char *response,
-    if (pasynUser->reason == motorCanDisable_) {
+                                                      int axisNo,
-        *value = 1;
+                                                      const char *functionName,
-        return asynSuccess;
+                                                      int lineNumber) {
-    } else {
-        return asynMotorController::readInt32(pasynUser, value);
-    }
-}
-
-asynStatus turboPmacController::errMsgCouldNotParseResponse(
-    const char *command, const char *response, int axisNo,
-    const char *functionName, int lineNumber) {
     char modifiedResponse[MAXBUF_] = {0};
     adjustResponseForPrint(modifiedResponse, response, MAXBUF_);
-    return sinqController::errMsgCouldNotParseResponse(
+    return sinqController::couldNotParseResponse(
         command, modifiedResponse, axisNo, functionName, lineNumber);
 }
 
@@ -549,8 +515,8 @@ asynStatus turboPmacCreateController(const char *portName,
     https://github.com/epics-modules/motor/blob/master/motorApp/MotorSrc/asynMotorController.cpp
     https://github.com/epics-modules/asyn/blob/master/asyn/asynPortDriver/asynPortDriver.cpp
 
-    The created object is registered in EPICS in its constructor and can safely
+    The created object is registered in EPICS in its constructor and can
-    be "leaked" here.
+    safely be "leaked" here.
     */
 #pragma GCC diagnostic ignored "-Wunused-but-set-variable"
 #pragma GCC diagnostic ignored "-Wunused-variable"
@@ -582,17 +548,17 @@ static const iocshArg CreateControllerArg5 = {"Communication timeout (s)",
 static const iocshArg *const CreateControllerArgs[] = {
     &CreateControllerArg0, &CreateControllerArg1, &CreateControllerArg2,
     &CreateControllerArg3, &CreateControllerArg4, &CreateControllerArg5};
-static const iocshFuncDef configturboPmacCreateController = {
+static const iocshFuncDef configTurboPmacCreateController = {
     "turboPmacController", 6, CreateControllerArgs};
 static void configTurboPmacCreateControllerCallFunc(const iocshArgBuf *args) {
     turboPmacCreateController(args[0].sval, args[1].sval, args[2].ival,
                               args[3].dval, args[4].dval, args[5].dval);
 }
 
-// This function is made known to EPICS in turboPmac.dbd and is called by EPICS
+// This function is made known to EPICS in turboPmac.dbd and is called by
-// in order to register both functions in the IOC shell
+// EPICS in order to register both functions in the IOC shell
 static void turboPmacControllerRegister(void) {
-    iocshRegister(&configturboPmacCreateController,
+    iocshRegister(&configTurboPmacCreateController,
                   configTurboPmacCreateControllerCallFunc);
 }
 epicsExportRegistrar(turboPmacControllerRegister);

src/turboPmacController.h

@@ -13,10 +13,10 @@
 #include "turboPmacAxis.h"
 
 class turboPmacController : public sinqController {
-
   public:
     /**
-     * @brief Construct a new turboPmacController object
+     * @brief Construct a new turboPmacController object. This function is meant
+    to be called from a child class constructor.
      *
      * @param portName            See sinqController constructor
      * @param ipPortConfigName    See sinqController constructor
@@ -26,10 +26,12 @@ class turboPmacController : public sinqController {
      * @param comTimeout          When trying to communicate with the device,
     the underlying asynOctetSyncIO interface waits for a response until this
     time (in seconds) has passed, then it declares a timeout.
+     * @param numExtraParams      Number of extra parameters from a child class
      */
     turboPmacController(const char *portName, const char *ipPortConfigName,
                         int numAxes, double movingPollPeriod,
-                        double idlePollPeriod, double comTimeout);
+                        double idlePollPeriod, double comTimeout,
+                        int numExtraParams = 0);
 
     /**
      * @brief Get the axis object
@@ -38,7 +40,7 @@ class turboPmacController : public sinqController {
      * @return turboPmacAxis*        If no axis could be found, this is a
      * nullptr
      */
-    turboPmacAxis *getAxis(asynUser *pasynUser);
+    turboPmacAxis *getTurboPmacAxis(asynUser *pasynUser);
 
     /**
      * @brief Get the axis object
@@ -47,7 +49,7 @@ class turboPmacController : public sinqController {
      * @return turboPmacAxis*        If no axis could be found, this is a
      * nullptr
      */
-    turboPmacAxis *getAxis(int axisNo);
+    turboPmacAxis *getTurboPmacAxis(int axisNo);
 
     /**
      * @brief Overloaded function of sinqController
@@ -58,10 +60,7 @@ class turboPmacController : public sinqController {
      * @param value               New value
      * @return asynStatus
      */
-    asynStatus writeInt32(asynUser *pasynUser, epicsInt32 value);
+    virtual asynStatus writeInt32(asynUser *pasynUser, epicsInt32 value);
-
-  protected:
-    asynUser *lowLevelPortUser_;
 
     /**
      * @brief Send a command to the hardware and receive a response
@@ -83,22 +82,13 @@ class turboPmacController : public sinqController {
                          int numExpectedResponses);
 
     /**
-     * @brief Save cast of the given asynAxis pointer to a turboPmacAxis
+     * @brief Specialized version of sinqController::couldNotParseResponse
-     * pointer. If the cast fails, this function returns a nullptr.
-     *
-     * @param asynAxis
-     * @return turboPmacAxis*
-     */
-    turboPmacAxis *castToAxis(asynMotorAxis *asynAxis);
-
-    /**
-     * @brief Specialized version of sinqController::errMsgCouldNotParseResponse
      * for turboPmac
      *
      * This is an overloaded version of
-     * sinqController::errMsgCouldNotParseResponse which calls
+     * sinqController::couldNotParseResponse which calls
      * adjustResponseForLogging on response before handing it over to
-     * sinqController::errMsgCouldNotParseResponse.
+     * sinqController::couldNotParseResponse.
      *
      * @param command             Command which led to the unparseable message
      * @param response            Response which wasn't parseable
@@ -109,17 +99,20 @@ class turboPmacController : public sinqController {
     called. It is recommended to use a macro, e.g. __LINE__.
      * @return asynStatus         Returns asynError.
      */
-    asynStatus errMsgCouldNotParseResponse(const char *command,
+    asynStatus couldNotParseResponse(const char *command, const char *response,
-                                           const char *response, int axisNo_,
+                                     int axisNo_, const char *functionName,
-                                           const char *functionName,
                                      int lineNumber);
 
-  private:
+    // Accessors for additional PVs
+    int rereadEncoderPosition() { return rereadEncoderPosition_; }
+    int readConfig() { return readConfig_; }
+
     // Set the maximum buffer size. This is an empirical value which must be
     // large enough to avoid overflows for all commands to the device /
     // responses from it.
     static const uint32_t MAXBUF_ = 200;
 
+  protected:
     /*
     Timeout for the communication process in seconds
     */
@@ -132,8 +125,6 @@ class turboPmacController : public sinqController {
     int rereadEncoderPosition_;
     int readConfig_;
 #define LAST_turboPmac_PARAM readConfig_
-
-    friend class turboPmacAxis;
 };
 #define NUM_turboPmac_DRIVER_PARAMS                                            \
     (&LAST_turboPmac_PARAM - &FIRST_turboPmac_PARAM + 1)