RE: Beckhoff ADS to EPICS IOC

[GAGET Alexis via Tech-talk <tech-talk at aps.anl.gov>]

Hi Lesley,

Already at least 2 solutions for ADS EPICS drivers exist in the community:

https://github.com/epics-modules/twincat-ads/

https://epics.cosylab.com/documentation/adsDriver/

 

Why not using those ones ?

 

At minimum it can maybe be used as an example if you want to keep going on your solution J

 

Cheers

 

Alexis

CEA/Irfu/DIS

 

De : Tech-talk <tech-talk-bounces at aps.anl.gov> De la part de Lesley via Tech-talk
Envoyé : jeudi 5 juin 2025 17:08
À : tech-talk at aps.anl.gov
Objet : Beckhoff ADS to EPICS IOC

 

Hello!

I developed a Beckhoff ADS IOC application using this ADS driver (https://github.com/Beckhoff/ADS). After the IOC runs for some time, the following issue occurs: "WARNING dbEvent possible queue stall". Concurrently, the PVs in the OPI will disconnect and then automatically reconnect after a short period.

Here's a code snippet for reading data from the PLC using the ADS driver:

extern "C" {

struct WaterStatusStruct adsReadWaterStatusValue(){

        WaterStatusStruct CWStatusVar; 

        const std::string handleName = "GVL_RFQ.water_status";

        //Use mutex locks to protect access

        std::lock_guard<std::mutex> lock(plcMutex);

        

        const long handleStatus = AdsSyncReadWriteReqEx2(port,

                                                        &plcAddress,

                                                        ADSIGRP_SYM_HNDBYNAME,

                                                        0,

                                                        sizeof(handle),

                                                        &handle,

                                                        handleName.size(),

                                                        handleName.c_str(),

                                                        nullptr);

        if (handleStatus) {

            printf("adsReadWaterStatusValue Create handle failed with: %8lX\n", handleStatus);

            //out << "Create handle for '" << handleName << "' failed with: 0x" << std::hex << handleStatus << '\n';

            return CWStatusVar;

        }

 

        const long status2 = AdsSyncReadReqEx2(port,

                                                &plcAddress,

                                                ADSIGRP_SYM_VALBYHND,

                                                handle,

                                                sizeof(CWStatusVar),

                                                &CWStatusVar,

                                                &bytesRead);

        if (status2) {

                printf("adsReadWaterStatusValue ADS read failed with: %8lX\n", status2);

                //out << "ADS read failed with: " << std::dec << status << '\n';

                

        }

        const long releaseHandle = AdsSyncWriteReqEx(port, &plcAddress, ADSIGRP_SYM_RELEASEHND, 0, sizeof(handle), &handle);

        if (releaseHandle) {

            //out << "Release handle 0x" << std::hex << handle << "' failed with: 0x" << releaseHandle << '\n';

            printf("adsReadWaterStatusValue Release handle failed\n");

        }

 

    

        return CWStatusVar;

    } 

}

 

What can I do to fix this?Thank you for your time.