Omnet++ No Gate Index specified when accessing vector gate - omnet++

Question

I'm asking about a ring topology network, I'm looking to send a message from the node to hub and then to another node then back to the hub but when it simulates there is an error that pops up. I'm not sure what is the issue.
send()/sendDelayed(): No gate index specified when accessing vector gate 'out' -- in module (node) Startop.node[0] (id=2), during network initialization
Here is my .ned file:
package startop;
simple node
{
parameters:
#display("i=device/pc2_s");
gates:
input in[];
output out[];
}
simple hub
{
parameters:
#display("i=device/switch");
gates:
input in[];
output out[];
}
network Startop
{
parameters:
int n #prompt("Number of stations") = default(2);
submodules:
node[n]: node;
hub: hub {
#display("p=222,170");
}
connections allowunconnected:
for i=0..n-1 {
node[i].out++ --> hub.in++;
hub.out++ --> node[i].in++;
}
}
This is the .cc file:
#include <stdio.h>
#include <string.h>
#include <omnetpp.h>
using namespace omnetpp;
class node : public cSimpleModule
{
private:
simtime_t timeout; // timeout
cMessage *timeoutEvent; // holds pointer to the timeout self-message
public:
node();
virtual ~node();
protected:
virtual void initialize() override;
virtual void handleMessage(cMessage *msg) override;
};
Define_Module(node);
node::node()
{
timeoutEvent = nullptr;
}
node::~node()
{
cancelAndDelete(timeoutEvent);
}
void node::initialize()
{
// Initialize variables.
timeout = 1.0;
timeoutEvent = new cMessage("timeoutEvent");
// Generate and send initial message.
EV << "Sending initial message\n";
cMessage *msg = new cMessage("StarMsg");
send(msg, "out");
scheduleAt(simTime()+timeout, timeoutEvent);
}
void node::handleMessage(cMessage *msg)
{
if (msg == timeoutEvent) {
// If we receive the timeout event, that means the packet hasn't
// arrived in time and we have to re-send it.
EV << "Timeout expired, resending message and restarting timer\n";
cMessage *newMsg = new cMessage("StarMsg");
send(newMsg, "out");
scheduleAt(simTime()+timeout, timeoutEvent);
}
else { // message arrived
// Acknowledgement received -- delete the received message and cancel
// the timeout event.
EV << "Timer cancelled.\n";
cancelEvent(timeoutEvent);
delete msg;
// Ready to send another one.
cMessage *newMsg = new cMessage("starMsg");
send(newMsg, "out");
scheduleAt(simTime()+timeout, timeoutEvent);
}
}
class hub : public cSimpleModule
{
protected:
virtual void handleMessage(cMessage *msg) override;
};
Define_Module(hub);
void hub::handleMessage(cMessage *msg)
{
if (uniform(0, 1) < 0.1) {
EV << "\"Losing\" message.\n";
bubble("message lost"); // making animation more informative...
delete msg;
}
else {
EV << "Sending back same message as acknowledgement.\n";
send(msg, "out");
}
}
May I know how to solve this problem?

Answer 1

The issue is exactly what the error message said. The NED file defines the out gate a vector both in node and hub:
output out[];
However your c++ code always uses the send method send(msg, "out") without specifying which out gate should be used. i.e. it never specifies the index. You must use the send(msg, "out", getIndex) for this.