Qt ActiveX "Unknown error" - qt

Question

I'm working on integrating T-Cube motor controller (http://www.thorlabs.de/newgrouppage9.cfm?objectgroup_id=2419) into the software based on Qt-4.8.1 package. Due to there is no manual or any sort of tutorial how to retrieve ActiveX object and how to call methods I did the following.
1) Looked through Windows registry looking for words similar to motor controller name. Found a candidate with CLSID "{3CE35BF3-1E13-4D2C-8C0B-DEF6314420B3}".
2) Tried initializing it in the following way (code provided is shortened, all result checks are removed in order to improve readability):
HRESULT h_result = CoInitializeEx(NULL, COINIT_MULTITHREADED);
pd->moto = new QAxObject();
initialized = moto->setControl( "{3CE35BF3-1E13-4D2C-8C0B-DEF6314420B3}" );
QString stri = browser->generateDocumentation();
obj->dynamicCall("SetHWSerialNum(int)", params);
QVariantList params;
params << 0;
params << 0.0;
int result = pd->moto->dynamicCall("GetPosition(int, double&)", params).toInt();
value = params[1].toFloat();
QVariantList params;
params << 0;
params << dist;
params << dist;
params << true;
int result = pd->moto->dynamicCall("MoveRelativeEx(int, double, double, bool)", params).toInt();
3) generateDocumentation() method gives perfect description of ~150 methods.
4) All dynamicCall() invocations cause "Error calling ...: Unknown error", where "..." is a first argument of dynamicCall() from the list generateDocumentation()'s given me.
5) If I insert into dynamicCall() any method which isn't presented in the documentation generated the output is different. So I suppose that methods in documentation generated really exist.
6) If I use #import directive and try calling directly avoiding QAxObject usage I see "mg17motor.tlh" file but none of interfaces described there contain any methods. So I can't use it directly as well. Is it normal?
I would be very much obliged for any advice.

Answer 1

You can find the ActiveX object using the OLE viewer. Then search for something like
APT.. or MG.. under all objects. Then find the parameter ProgID=MGMOTOR.MGMotorCtrl.1.
Now in Qt don't use QAxObject but QAxWidget. Then you get something like:
QAxWidget* aptMotor;
QVariant chanID = QVariant(0);
aptMotor = new QAxWidget();
aptMotor->setControl("MGMOTOR.MGMotorCtrl.1");
//Nice html documentation on available functions
QFile file("out.html");
file.open(QIODevice::WriteOnly | QIODevice::Text);
QTextStream out(&file);
out << aptMotor->generateDocumentation();
file.close();
aptMotor->setProperty("HWSerialNum",QVariant(83853493));
aptMotor->dynamicCall("StartCtrl");
aptMotor->dynamicCall("EnableHWChannel(QVariant)",chanID);
QThread::sleep(1); // Give it time to enable the channel
double pos(0);
aptMotor->dynamicCall("SetAbsMovePos(QVariant,QVariant)",chanID,QVariant(pos));
aptMotor->dynamicCall("MoveAbsolute(QVariant,QVariant,QVariant)",chanID,0);
aptMotor->dynamicCall("StopCtrl");