Connection Close by remote while opening twincat project file at the same time #274
Description
Hi All
I successfully compiled and run the project. But when I open twincat file, some times the data intermittent and connection becoming close. I need to close twincat file then I can read the value. Btw i am just using "notificationByNameExample" only. Below is the error:
_notificationByNameExample():
Hit ENTER to stop by name notifications
2025-11-03T12:11:34 Warning: No dispatcher found for notification
hUser 0xbeefdead sample time: 134066168684460000 sample size: 4 value: 0x51.2464
2025-11-03T12:11:35 Warning: No dispatcher found for notification
hUser 0xbeefdead sample time: 134066168688460000 sample size: 4 value: 0x74.2235
hUser 0xbeefdead sample time: 134066168692460000 sample size: 4 value: 0x49.0491
2025-11-03T12:11:35 Warning: No dispatcher found for notification
hUser 0xbeefdead sample time: 134066168696460000 sample size: 4 value: 0x33.3125
2025-11-03T12:11:36 Warning: No dispatcher found for notification
hUser 0xbeefdead sample time: 134066168700460000 sample size: 4 value: 0x29.3574
2025-11-03T12:11:36 Warning: No dispatcher found for notification
hUser 0xbeefdead sample time: 134066168704460000 sample size: 4 value: 0x16.3216
2025-11-03T12:11:37 Warning: No dispatcher found for notification
hUser 0xbeefdead sample time: 134066168708460000 sample size: 4 value: 0x11.8156
hUser 0xbeefdead sample time: 134066168712460000 sample size: 4 value: 0x83.4659
2025-11-03T12:11:37 Warning: No dispatcher found for notification
hUser 0xbeefdead sample time: 134066168716460000 sample size: 4 value: 0x28.3899
2025-11-03T12:11:38 Warning: No dispatcher found for notification
hUser 0xbeefdead sample time: 134066168720460000 sample size: 4 value: 0x68.6783
2025-11-03T12:11:38 Warning: No dispatcher found for notification
hUser 0xbeefdead sample time: 134066168724460000 sample size: 4 value: 0x56.5138
2025-11-03T12:11:39 Warning: No dispatcher found for notification
hUser 0xbeefdead sample time: 134066168728460000 sample size: 4 value: 0x12.3619
2025-11-03T12:11:39 Info: connection closed by remote_
Can I know how I can read the value without connection closed by remote?
I also refer to this link: https://infosys.beckhoff.com/english.php?content=../content/1033/tc3_adsdll2/index.html&id=
i believe it can be done by AdsSyncAddDeviceNotificationReq, AdsSyncDelDeviceNotificationReq and AdsPortClose(), means
if got error while reading the value, so i can refresh connection by delete notfication, port close and add device notification request again.
I tried from sample link above but seems no respond:
`Error: AdsSyncReadWriteReq: 7
Error: AdsSyncAddDeviceNotificationReq: 7
Notification: 32758
`
Below is my full code, i only modified example/example.cpp
#include "AdsLib.h"
#include "AdsNotificationOOI.h"
#include "AdsVariable.h"
#include <array>
#include <cstring>
#include <iostream>
#include <iomanip>
#include <thread>
#include <conio.h>
using ExampleDatatype = float; //uint8_t
//Callback(AmsAddr* pAddr, AdsNotificationHeader* pNotification, ULONG hUser )
void NotifyCallback(const AmsAddr *pAddr, const AdsNotificationHeader *pNotification, uint32_t hUser)
{
// std::this_thread::sleep_for(std::chrono::seconds(1));
ExampleDatatype data{};
std::memcpy(&data, pNotification + 1,
std::min<size_t>(sizeof(data),
pNotification->cbSampleSize));
std::cout
// << std::setfill('0') << "NetId: " << pAddr->netId
<< " hUser 0x" << std::hex << hUser
<< " sample time: " << std::dec << pNotification->nTimeStamp
<< " sample size: " << std::dec << pNotification->cbSampleSize
<< " value:" << " 0x" << std::hex << +data << '\n';
}
static void notificationExample(std::ostream &out, const AdsDevice &route)
{
const AdsNotificationAttrib attrib = {
sizeof(ExampleDatatype), ADSTRANS_SERVERCYCLE, 0, { 4000000 }
};
AdsNotification notification{ route, 0x4020, 4,
attrib, &NotifyCallback, 0xDEADBEEF };
out << "Hit ENTER to stop notifications\n";
std::cin.ignore();
}
static void notificationByNameExample(std::ostream &out, const AdsDevice &route)
{
const AdsNotificationAttrib attrib = {
sizeof(ExampleDatatype), ADSTRANS_SERVERONCHA, 0, { 4000000 }
};
out << __FUNCTION__ << "():\n";
AdsNotification notification{ route, "GVL.dummy_flow1", attrib,
&NotifyCallback, 0xBEEFDEAD };
out << "Hit ENTER to stop by name notifications\n";
std::cin.ignore();
}
static void readExample(std::ostream &out, const AdsDevice &route)
{
AdsVariable<uint8_t> readVar{ route, 0x4020, 0 };
out << __FUNCTION__ << "():\n";
for (size_t i = 0; i < 8; ++i) {
out << "ADS read " << std::hex << (uint32_t)readVar << '\n';
}
}
static void readByNameExample(std::ostream &out, const AdsDevice &route)
{
AdsVariable<uint8_t> readVar{ route, "MAIN.byByte[4]" };
out << __FUNCTION__ << "():\n";
for (size_t i = 0; i < 8; ++i) {
out << "ADS read " << std::hex << (uint32_t)readVar << '\n';
}
}
static void readWriteExample(std::ostream &out, const AdsDevice &route)
{
AdsVariable<uint8_t> simpleVar{ route, "MAIN.byByte[0]" };
AdsVariable<uint8_t> validation{ route, "MAIN.byByte[0]" };
out << __FUNCTION__ << "():\n";
simpleVar = 0xA5;
out << "Wrote " << 0xA5 << " to MAIN.byByte and read "
<< (uint32_t)validation << " back\n";
simpleVar = 0x5A;
out << "Wrote " << (uint32_t)simpleVar << " to MAIN.byByte and read "
<< (uint32_t)validation << " back\n";
}
static void readWriteArrayExample(std::ostream &out, const AdsDevice &route)
{
static const std::array<uint8_t, 4> arrayToWrite = { 1, 2, 3, 4 };
AdsVariable<std::array<uint8_t, 4> > arrayVar{ route, "MAIN.byByte" };
arrayVar = arrayToWrite;
std::array<uint8_t, 4> readArray = arrayVar;
out << "Wrote array with first value " << (uint32_t)arrayToWrite[0]
<< " and last value " << (uint32_t)arrayToWrite[3] << "\n";
out << "Read back array with first value " << (uint32_t)readArray[0]
<< " and last value " << (uint32_t)readArray[3] << "\n";
}
static void readStateExample(std::ostream &out, const AdsDevice &route)
{
const auto state = route.GetState();
out << "ADS state: " << std::dec << (uint16_t)state.ads
<< " devState: " << std::dec << (uint16_t)state.device << '\n';
}
static void runExample(std::ostream &out)
{
static const AmsNetId remoteNetId{ 172,17,10,5,1,1 };
static const char remoteIpV4[] = "192.168.100.154";
// uncomment and adjust if automatic AmsNetId deduction is not working as expected
bhf::ads::SetLocalAddress({192,168,232,1,1,1});
AdsDevice route{ remoteIpV4, remoteNetId, AMSPORT_R0_PLC_TC3 };
// AmsAddr* pAddr;
// AdsGetLocalAddressEx(AMSPORT_R0_PLC_TC3, pAddr);
//notificationExample(out, route);
notificationByNameExample(out, route);
//readExample(out, route);
// readByNameExample(out, route);
// readWriteExample(out, route);
// readWriteArrayExample(out, route);
// readStateExample(out, route);
}
/*
int main()
{
try {
runExample(std::cout);
} catch (const AdsException &ex) {
std::cout << "Error: " << ex.errorCode << "\n";
std::cout << "AdsException message: " << ex.what() << "\n";
} catch (const std::runtime_error &ex) {
std::cout << ex.what() << '\n';
}
std::cout << "Hit ENTER to continue\n";
std::cin.ignore();
}
//*/
///*
int main()
{
long nErr, nPort;
AmsAddr *pAddr;
AmsNetId remoteNetId{ 172,17,10,5,1,1 };
pAddr->netId = remoteNetId;
//PAmsAddr pAddr = &Addr;
uint32_t hNotification, hUser, cbReturn;
AdsNotificationAttrib adsNotificationAttrib;
char szVar []={"GVL.dummy_flow1"};
// open communication port on the ADS router
nPort = AdsPortOpenEx();
// nErr = AdsGetLocalAddressEx(851, pAddr);
//if (nErr) std::cerr << "Error: AdsGetLocalAddress: " << nErr << '\n';
// TwinCAT 3 RTS1 Port = 851
pAddr->port = 851;
// set the attributes of the notification
adsNotificationAttrib.cbLength = 4;
adsNotificationAttrib.nTransMode = ADSTRANS_SERVERONCHA;
adsNotificationAttrib.nMaxDelay = 0;
adsNotificationAttrib.nCycleTime = 10000000; // 1sec
// get handle
// AdsSyncReadWriteReqEx2
nErr = AdsSyncReadWriteReqEx2(pAddr->port, pAddr, ADSIGRP_SYM_HNDBYNAME, 0x0, sizeof(hUser), &hUser, sizeof(szVar), szVar, &cbReturn);
if (nErr) std::cerr << "Error: AdsSyncReadWriteReq: " << nErr << '\n';
// initiate the transmission of the PLC-variable
nErr = AdsSyncAddDeviceNotificationReqEx(pAddr->port, pAddr, ADSIGRP_SYM_VALBYHND, hUser, &adsNotificationAttrib, NotifyCallback, hUser, &hNotification);
if (nErr) std::cerr << "Error: AdsSyncAddDeviceNotificationReq: " << nErr << '\n';
std::cout << "Notification: " << hNotification << "\n\n";
std::cout.flush();
// wait for user intraction (keystroke)
getch();
// finish the transmission of the PLC-variable
nErr = AdsSyncDelDeviceNotificationReqEx(pAddr->port, pAddr, hNotification);
if (nErr) std::cerr << "Error: AdsSyncDelDeviceNotificationReq: " << nErr << '\n';
// release handle
nErr = AdsSyncWriteReqEx(pAddr->port,pAddr, ADSIGRP_SYM_RELEASEHND, 0, sizeof(hUser), &hUser);
if (nErr) std::cerr << "Error: AdsSyncWriteReq: " << nErr << '\n';
// Close the communication port
nErr = AdsPortCloseEx(pAddr->port);
if (nErr) std::cerr << "Error: AdsPortClose: " << nErr << '\n';
}
//*/
Can some one help me on this? thanks :)