Modified communication protocol for MCU software 2.0

Makefile

@@ -13,7 +13,7 @@ REQUIRED+=sinqMotor
 motorBase_VERSION=7.2.2
 
 # Specify the version of sinqMotor we want to build against
-sinqMotor_VERSION=0.8.0
+sinqMotor_VERSION=mathis_s
 
 # These headers allow to depend on this library for derived drivers.
 HEADERS += src/masterMacsAxis.h

README.md

@@ -4,6 +4,8 @@
 
 This is a driver for the masterMacs 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.
 
+Compatible to MasterMACS software 2.0.0.
+
 ## User guide
 
 This driver is a standard sinqMotor-derived driver and does not need any specific configuration. For the general configuration, please see https://git.psi.ch/sinq-epics-modules/sinqmotor/-/blob/main/README.md.

src/masterMacsAxis.cpp

@@ -303,6 +303,34 @@ asynStatus masterMacsAxis::doPoll(bool *moving) {
 
     // Are we currently waiting for a handshake?
     if (waitForHandshake_) {
+
+        // Check if the handshake takes too long and communicate an error in
+        // this case. A handshake should not take more than 5 seconds.
+        time_t currentTime = time(NULL);
+        bool timedOut = (currentTime > timeAtHandshake_ + 5);
+
+        if (pC_->msgPrintControl_.shouldBePrinted(
+                pC_->portName, axisNo_, __PRETTY_FUNCTION__, __LINE__, timedOut,
+                pC_->pasynUserSelf)) {
+            asynPrint(pC_->pasynUserSelf, ASYN_TRACE_ERROR,
+                      "Controller \"%s\", axis %d  => %s, line %d\nAsked for a "
+                      "handshake at %ld s and didn't get a positive reply yet "
+                      "(current time is %ld s).\n",
+                      pC_->portName, axisNo_, __PRETTY_FUNCTION__, __LINE__,
+                      timeAtHandshake_, currentTime);
+        }
+
+        if (timedOut) {
+            pl_status =
+                setStringParam(pC_->motorMessageText_,
+                               "Timed out while waiting for a handshake");
+            if (pl_status != asynSuccess) {
+                return pC_->paramLibAccessFailed(pl_status, "motorMessageText_",
+                                                 axisNo_, __PRETTY_FUNCTION__,
+                                                 __LINE__);
+            }
+        }
+
         pC_->read(axisNo_, 86, response);
         if (rw_status != asynSuccess) {
             return rw_status;
@@ -580,7 +608,7 @@ asynStatus masterMacsAxis::doPoll(bool *moving) {
             }
         }
     } else {
-        pC_->msgPrintControl_.resetCount(keyError);
+        pC_->msgPrintControl_.resetCount(keyError, pC_->pasynUserSelf);
     }
 
     // Read out the limits, if the motor is not moving

src/masterMacsController.cpp

@@ -84,10 +84,9 @@ masterMacsController::masterMacsController(const char *portName,
     /*
     Define the end-of-string of a message coming from the device to EPICS.
     It is not necessary to append a terminator to outgoing messages, since
-    the message length is encoded in the message header in the getSetResponse
+    the message length is encoded in the message header.
-    method.
     */
-    const char *message_from_device = "\x03"; // Hex-code for ETX
+    const char *message_from_device = "\x0D"; // Hex-code for CR
     status = pasynOctetSyncIO->setInputEos(
         lowLevelPortUser_, message_from_device, strlen(message_from_device));
     if (status != asynSuccess) {
@@ -180,52 +179,17 @@ asynStatus masterMacsController::writeRead(int axisNo, int tcpCmd,
         return asynError;
     }
 
-    /*
+    // TODO: CR at the end
-    PSI SINQ uses a custom protocol which is described in
-    PSI_TCP_Interface_V1-8.pdf (p. // 4-17).
-    A special case is the message length, which is specified by two bytes
-    LSB and MSB: MSB = message length / 256 LSB = message length % 256. For
-    example, a message length of 47 chars would result in MSB = 0, LSB = 47,
-    whereas a message length of 356 would result in MSB = 1, LSB = 100.
-
-    The full protocol looks as follows:
-    0x05 -> Start of protocol frame ENQ
-    [LSB]
-    [MSB]
-    0x19 -> Data type PDO1
-    value [Actual message] It is not necessary to append a terminator, since
-    this protocol encodes the message length in LSB and MSB.
-    0x0D -> Carriage return (ASCII alias \r)
-    0x03 -> End of text ETX
-    */
-
-    fullCommand[0] = '\x05'; // ENQ
-    fullCommand[1] = 1;      // Placeholder value, can be anything other than 0
-    fullCommand[2] = 1;      // Placeholder value, can be anything other than 0
-    fullCommand[3] = '\x19'; // PD01
-
-    // Create the command and add CR and ETX at the end
     if (isRead) {
-        snprintf(&fullCommand[4], MAXBUF_ - 4, "%dR%02d\x0D\x03", axisNo,
+        snprintf(fullCommand, MAXBUF_ - 1, "%dR%02d\x0D", axisNo, tcpCmd);
-                 tcpCmd);
     } else {
-        snprintf(&fullCommand[4], MAXBUF_ - 4, "%dS%02d=%s\x0D\x03", axisNo,
+        snprintf(fullCommand, MAXBUF_ - 1, "%dS%02d=%s\x0D", axisNo, tcpCmd,
-                 tcpCmd, payload);
+                 payload);
     }
 
     // Calculate the command length
     const size_t fullCommandLength = strlen(fullCommand);
 
-    // Length of the command without ENQ and ETX
-    const size_t lenWithMetadata = fullCommandLength - 2;
-
-    // Perform both division and modulo operation at once.
-    div_t lenWithMetadataSep = std::div(lenWithMetadata, 256);
-
-    // Now set the actual command length
-    fullCommand[1] = lenWithMetadataSep.rem;  // LSB
-    fullCommand[2] = lenWithMetadataSep.quot; // MSB
-
     adjustForPrint(printableCommand, fullCommand, MAXBUF_);
 
     // Send out the command
@@ -237,14 +201,30 @@ asynStatus masterMacsController::writeRead(int axisNo, int tcpCmd,
         msgPrintControlKey(portName, axisNo, __PRETTY_FUNCTION__, __LINE__);
 
     if (status == asynSuccess) {
-        msgPrintControl_.resetCount(writeKey);
+        msgPrintControl_.resetCount(writeKey, pasynUserSelf);
 
         // Try to read the answer repeatedly
         int maxTrials = 2;
         for (int i = 0; i < maxTrials; i++) {
+
+            /*
+            A typical response of the MasterMacs controller looks like this:
+            (.. TCP Header ...) 31 20 52 20 31 31 3d 35 31 32 2e 30 30 30 30 06
+            0d 00 00 00 00 00 00 00 00 00 00 00 00 00
+            The message terminator is the carriage return (0d), which is
+            specified in the controller constructor as the end-of-string (EOS)
+            character. However, we also need to remove the buffer zeros at the
+            end, because they will otherwise confuse the
+            pasynOctetSyncIO->read() during the next call. The
+            pasynOctetSyncIO->flush() method does exactly that: it takes all
+            bytes it can find in the socket and throws them away. We don't check
+            the return value of flush(), because it is always asynSuccess (see
+            https://www.slac.stanford.edu/grp/lcls/controls/global/doc/epics-modules/R3-14-12/asyn/asyn-R4-18-lcls2/asyn/interfaces/asynOctetBase.c)
+             */
             status =
                 pasynOctetSyncIO->read(lowLevelPortUser_, fullResponse, MAXBUF_,
                                        comTimeout_, &nbytesIn, &eomReason);
+            pasynOctetSyncIO->flush(lowLevelPortUser_);
 
             if (status == asynSuccess) {
                 status = parseResponse(fullCommand, fullResponse,
@@ -283,10 +263,6 @@ asynStatus masterMacsController::writeRead(int axisNo, int tcpCmd,
         }
     }
 
-    // MasterMACS needs a bit of time between messages, therefore thr
-    // program execution is paused after the communication happened.
-    // usleep(1500);
-
     // Create custom error messages for different failure modes
     switch (status) {
     case asynSuccess:
@@ -434,7 +410,7 @@ asynStatus masterMacsController::parseResponse(
     }
 
     if (responseValid) {
-        msgPrintControl_.resetCount(parseKey);
+        msgPrintControl_.resetCount(parseKey, pasynUserSelf);
 
         // Check if the response matches the expectations. Each response
         // contains the string "axisNo R tcpCmd" (including the spaces)
@@ -475,7 +451,7 @@ asynStatus masterMacsController::parseResponse(
                      printableResponse, printableCommand);
             return asynError;
         } else {
-            msgPrintControl_.resetCount(responseMatchKey);
+            msgPrintControl_.resetCount(responseMatchKey, pasynUserSelf);
         }
     }
     return asynSuccess;