VISA: Add methods to get available resources. Make I/O logging optional. Check for errors in processCommands.

sdrbase/util/visa.cpp

@@ -16,6 +16,7 @@
 ///////////////////////////////////////////////////////////////////////////////////
 
 #include <QDebug>
+#include <QRegularExpression>
 
 #include "visa.h"
 
@@ -48,6 +49,8 @@ VISA::VISA() :
         viClose = (ViStatus (*)(ViObject vi)) libraryFunc(visaLibrary, "viClose");
         viPrintf = (ViStatus (*) (ViSession vi, ViString writeFmt, ...)) libraryFunc(visaLibrary, "viPrintf");
         viScanf = (ViStatus (*) (ViSession vi, ViString writeFmt, ...)) libraryFunc(visaLibrary, "viScanf");
+        viFindRsrc = (ViStatus (*) (ViSession vi, ViString expr, ViPFindList li, ViPUInt32 retCnt, ViChar desc[])) libraryFunc(visaLibrary, "viFindRsrc");
+        viFindNext = (ViStatus (*) (ViSession vi, ViChar desc[])) libraryFunc(visaLibrary, "viFindNext");
 
         if (viOpenDefaultRM && viOpen && viClose && viPrintf) {
             m_available = true;
@@ -106,32 +109,130 @@ void VISA::close(ViSession session)
     }
 }
 
-QStringList VISA::processCommands(ViSession session, const QString& commands)
+QStringList VISA::processCommands(ViSession session, const QString& commands, bool *error)
 {
     QStringList list = commands.split("\n");
     QStringList results;
+    ViStatus status;
+
+    if (error) {
+        *error = false;
+    }
     for (int i = 0; i < list.size(); i++)
     {
         QString command = list[i].trimmed();
         if (!command.isEmpty() && !command.startsWith("#"))   // Allow # to comment out lines
         {
-            qDebug() << "VISA ->: " << command;
+            if (m_debugIO) {
+                qDebug() << "VISA ->: " << command;
+            }
             QByteArray bytes = QString("%1\n").arg(command).toLatin1();
             char *cmd = bytes.data();
-            viPrintf(session, cmd);
+            status = viPrintf(session, cmd);
-            if (command.endsWith("?"))
+            if (error && status) {
+                *error = true;
+            }
+            if (command.contains("?"))
             {
                 char buf[1024] = "";
                 char format[] = "%t";
-                viScanf(session, format, buf);
+                status = viScanf(session, format, buf);
+                if (error && status) {
+                    *error = true;
+                }
                 results.append(buf);
-                qDebug() << "VISA <-: " << QString(buf).trimmed();
+                if (m_debugIO) {
+                    qDebug() << "VISA <-: " << QString(buf).trimmed();
+                }
             }
         }
     }
     return results;
 }
 
+QStringList VISA::findResources()
+{
+    QStringList resources;
+    ViChar rsrc[VI_FIND_BUFLEN];
+    ViFindList list;
+    ViRsrc matches = rsrc;
+    ViUInt32 nMatches = 0;
+    ViChar expr[] = "?*INSTR";
+
+    if (VI_SUCCESS == viFindRsrc(m_defaultRM, expr, &list, &nMatches, matches))
+    {
+        if (nMatches > 0)
+        {
+            resources.append(QString(rsrc));
+            while (VI_SUCCESS == viFindNext(list, matches))
+            {
+                resources.append(QString(rsrc));
+            }
+        }
+    }
+    return resources;
+}
+
+bool VISA::identification(ViSession session, QString &manufacturer, QString &model, QString &serialNumber, QString &revision)
+{
+    QStringList result = processCommands(session, "*IDN?");
+    if ((result.size() == 1) && (!result[0].isEmpty()))
+    {
+        QStringList details = result[0].trimmed().split(',');
+        manufacturer = details[0];
+        // Some serial devices (ASRLn) loop back the the command if not connected
+        if (manufacturer == "*IDN?") {
+            return false;
+        }
+        if (details.size() >= 2) {
+            model = details[1];
+        }
+        if (details.size() >= 3) {
+            serialNumber = details[2];
+        }
+        if (details.size() >= 4) {
+            revision = details[3];
+        }
+        qDebug() << "VISA::identification: "
+                 << "manufacturer: " << manufacturer
+                 << "model: " << model
+                 << "serialNumber: " << serialNumber
+                 << "revision: " << revision;
+        return true;
+    }
+    return false;
+}
+
+// Filter is a list of resources not to try to open
+QList<VISA::Instrument> VISA::instruments(QRegularExpression *filter)
+{
+    QList<VISA::Instrument> instruments;
+    QStringList resourceList = findResources();
+
+    for (auto const &resource : resourceList)
+    {
+        if (filter)
+        {
+            if (filter->match(resource).hasMatch()) {
+                continue;
+            }
+        }
+        ViSession session = open(resource);
+        if (session)
+        {
+            Instrument instrument;
+            QString manufacturer, model, serialNumber, revision;
+            if (identification(session, instrument.m_manufacturer, instrument.m_model, instrument.m_serial, instrument.m_revision))
+            {
+                instrument.m_resource = resource;
+                instruments.append(instrument);
+            }
+            close(session);
+        }
+    }
+    return instruments;
+}
+
 #ifdef _MSC_VER
 
 void *VISA::libraryOpen(const char *filename)

sdrbase/util/visa.h

@@ -23,6 +23,10 @@
 
 #include "export.h"
 
+#include <QDebug>
+
+class QRegularExpression;
+
 typedef char ViChar;
 typedef ViChar * ViPChar;
 typedef signed long ViInt32;
@@ -35,17 +39,29 @@ typedef ViObject ViSession;
 typedef ViSession * ViPSession;
 typedef ViString ViRsrc;
 typedef ViUInt32 ViAccessMode;
+typedef ViUInt32 * ViPUInt32;
+typedef ViObject ViFindList;
+typedef ViFindList * ViPFindList;
 
 #define VI_SUCCESS 0
 #define VI_TRUE 1
 #define VI_FALSE 0
 #define VI_NULL 0
+#define VI_FIND_BUFLEN 256
 
 // We dynamically load the visa dll, as most users probably do not have it
 // Note: Can't seem to call viOpenDefaultRM/viClose in constructor / destructor of global instance
 class SDRBASE_API VISA {
 public:
 
+    struct Instrument {
+        QString m_resource;
+        QString m_manufacturer;
+        QString m_model;
+        QString m_serial;
+        QString m_revision;
+    };
+
     // Default session
     ViSession m_defaultRM;
     // Function pointers to VISA API for direct calls
@@ -54,6 +70,8 @@ public:
     ViStatus (*viClose) (ViObject vi);
     ViStatus (*viPrintf) (ViSession vi, ViString writeFmt, ...);
     ViStatus (*viScanf) (ViSession vi, ViString readFmt, ...);
+    ViStatus (*viFindRsrc) (ViSession vi, ViString expr, ViPFindList li, ViPUInt32 retCnt, ViChar desc[]);
+    ViStatus (*viFindNext) (ViSession vi, ViChar desc[]);
 
     VISA();
 
@@ -61,7 +79,11 @@ public:
     void closeDefault();
     ViSession open(const QString& device);
     void close(ViSession session);
-    QStringList processCommands(ViSession session, const QString& commands);
+    QStringList processCommands(ViSession session, const QString& commands, bool *error=nullptr);
+    QStringList findResources();
+    bool identification(ViSession session, QString &manufacturer, QString &model, QString &serialNumber, QString &revision);
+    QList<Instrument> instruments(QRegularExpression *filter);
+    void setDebugIO(bool debugIO) { m_debugIO = debugIO; }
 
     // Is the VISA library available
     bool isAvailable() const
@@ -71,6 +93,7 @@ public:
 
 private:
     bool m_available;
+    bool m_debugIO;
 
 protected:
     void *visaLibrary;