occasionally，sent the correct data to the PLC, but the data is still the same as before

[minterjiang]

2026 05-25 15:23:02 958|Debug|IoLoopAsync|Write 6 data items: RJET-ZSP-L9-03989,41022,0,200807281,1,1

After the last writing, on-site feedback showed that the tray number remained the same as the previous data RJET-ZSP-L9-03255, not RJET-ZSP-L9-03989
Later, the task was reissued and reissued again:
2026 05-25 15:31:25 220 | Debug | IoLoopSync | Write 6 data items: RJET-ZSP-L9-038994022, 0200807281, 1,1

The data packets of the two times were identical, but the first time the tray number was not updated successfully, the second time it was successful, and the network layer PLC did not report any abnormality.

In the vast majority of cases, it is normal for occasional writes of a few thousand times to occur a few times

[ynioba]

这是来自”麦冬@广西机械工业研究院”的邮箱自动回复邮件。您好，您的邮件已收到，我查阅后尽快回复您。

[minterjiang]

this picture was after 2026 05-25 15:23:02 958 write 6 data , palletid is RJET-ZSP-L9-03255 is not RJET-ZSP-L9-03899.

[minterjiang]

`
the first time request：
Frame 5676303: 205 bytes on wire (1640 bits), 205 bytes captured (1640 bits) on interface \Device\NPF_{0441D740-045B-4588-A4DA-874A48E65C3A}, id 0
Ethernet II, Src: HuaweiTechno_1d:90:5a (a4:dc:be:1d:90:5a), Dst: HuaweiTechno_c2:aa:95 (10:24:07:c2:aa:95)
Destination: HuaweiTechno_c2:aa:95 (10:24:07:c2:aa:95)
.... ..0. .... .... .... .... = LG bit: Globally unique address (factory default)
.... ...0 .... .... .... .... = IG bit: Individual address (unicast)
Source: HuaweiTechno_1d:90:5a (a4:dc:be:1d:90:5a)
.... ..0. .... .... .... .... = LG bit: Globally unique address (factory default)
.... ...0 .... .... .... .... = IG bit: Individual address (unicast)
Type: IPv4 (0x0800)
[Stream index: 0]
Internet Protocol Version 4, Src: 172.30.53.4, Dst: 172.30.17.80
Transmission Control Protocol, Src Port: 58240, Dst Port: 102, Seq: 50620304, Ack: 37460198, Len: 151
TPKT, Version: 3, Length: 151
ISO 8073/X.224 COTP Connection-Oriented Transport Protocol
S7 Communication
Header: (Job)
Parameter: (Write Var)
Data
Item [1]: (Reserved)
Return code: Reserved (0x00)
Transport size: BYTE/WORD/DWORD (0x04)
Length: 22
Data: 1411524a45542d5a53502d4c392d3033393839000000
Item [2]: (Reserved)
Return code: Reserved (0x00)
Transport size: BYTE/WORD/DWORD (0x04)
Length: 4
Data: 0000a03e
Item [3]: (Reserved)
Return code: Reserved (0x00)
Transport size: BYTE/WORD/DWORD (0x04)
Length: 2
Data: 0000
Item [4]: (Reserved)
Return code: Reserved (0x00)
Transport size: BYTE/WORD/DWORD (0x04)
Length: 4
Data: 0bf81371
Item [5]: (Reserved)
Return code: Reserved (0x00)
Transport size: BYTE/WORD/DWORD (0x04)
Length: 2
Data: 0001
Item [6]: (Reserved)
Return code: Reserved (0x00)
Transport size: BYTE/WORD/DWORD (0x04)
Length: 2
Data: 0001

ACK_DATA
Frame 5676304: 81 bytes on wire (648 bits), 81 bytes captured (648 bits) on interface \Device\NPF_{0441D740-045B-4588-A4DA-874A48E65C3A}, id 0
Ethernet II, Src: HuaweiTechno_c2:aa:95 (10:24:07:c2:aa:95), Dst: HuaweiTechno_1d:90:5a (a4:dc:be:1d:90:5a)
Destination: HuaweiTechno_1d:90:5a (a4:dc:be:1d:90:5a)
.... ..0. .... .... .... .... = LG bit: Globally unique address (factory default)
.... ...0 .... .... .... .... = IG bit: Individual address (unicast)
Source: HuaweiTechno_c2:aa:95 (10:24:07:c2:aa:95)
.... ..0. .... .... .... .... = LG bit: Globally unique address (factory default)
.... ...0 .... .... .... .... = IG bit: Individual address (unicast)
Type: IPv4 (0x0800)
[Stream index: 0]
Internet Protocol Version 4, Src: 172.30.17.80, Dst: 172.30.53.4
Transmission Control Protocol, Src Port: 102, Dst Port: 58240, Seq: 37460198, Ack: 50620455, Len: 27
TPKT, Version: 3, Length: 27
ISO 8073/X.224 COTP Connection-Oriented Transport Protocol
S7 Communication
Header: (Ack_Data)
Parameter: (Write Var)
Data
Item [1]: (Success)
Return code: Success (0xff)
Item [2]: (Success)
Return code: Success (0xff)
Item [3]: (Success)
Return code: Success (0xff)
Item [4]: (Success)
Return code: Success (0xff)
Item [5]: (Success)
Return code: Success (0xff)
Item [6]: (Success)
Return code: Success (0xff)

second time request：
Frame 6352584: 205 bytes on wire (1640 bits), 205 bytes captured (1640 bits) on interface \Device\NPF_{0441D740-045B-4588-A4DA-874A48E65C3A}, id 0
Ethernet II, Src: HuaweiTechno_1d:90:5a (a4:dc:be:1d:90:5a), Dst: HuaweiTechno_c2:aa:95 (10:24:07:c2:aa:95)
Destination: HuaweiTechno_c2:aa:95 (10:24:07:c2:aa:95)
.... ..0. .... .... .... .... = LG bit: Globally unique address (factory default)
.... ...0 .... .... .... .... = IG bit: Individual address (unicast)
Source: HuaweiTechno_1d:90:5a (a4:dc:be:1d:90:5a)
.... ..0. .... .... .... .... = LG bit: Globally unique address (factory default)
.... ...0 .... .... .... .... = IG bit: Individual address (unicast)
Type: IPv4 (0x0800)
[Stream index: 0]
Internet Protocol Version 4, Src: 172.30.53.4, Dst: 172.30.17.80
Transmission Control Protocol, Src Port: 58240, Dst Port: 102, Seq: 56555196, Ack: 41852036, Len: 151
TPKT, Version: 3, Length: 151
ISO 8073/X.224 COTP Connection-Oriented Transport Protocol
S7 Communication
Header: (Job)
Parameter: (Write Var)
Data
Item [1]: (Reserved)
Return code: Reserved (0x00)
Transport size: BYTE/WORD/DWORD (0x04)
Length: 22
Data: 1411524a45542d5a53502d4c392d3033393839000000
Item [2]: (Reserved)
Return code: Reserved (0x00)
Transport size: BYTE/WORD/DWORD (0x04)
Length: 4
Data: 0000a03e
Item [3]: (Reserved)
Return code: Reserved (0x00)
Transport size: BYTE/WORD/DWORD (0x04)
Length: 2
Data: 0000
Item [4]: (Reserved)
Return code: Reserved (0x00)
Transport size: BYTE/WORD/DWORD (0x04)
Length: 4
Data: 0bf81371
Item [5]: (Reserved)
Return code: Reserved (0x00)
Transport size: BYTE/WORD/DWORD (0x04)
Length: 2
Data: 0001
Item [6]: (Reserved)
Return code: Reserved (0x00)
Transport size: BYTE/WORD/DWORD (0x04)
Length: 2
Data: 0001

ACK_DATA
Frame 6352594: 81 bytes on wire (648 bits), 81 bytes captured (648 bits) on interface \Device\NPF_{0441D740-045B-4588-A4DA-874A48E65C3A}, id 0
Ethernet II, Src: HuaweiTechno_c2:aa:95 (10:24:07:c2:aa:95), Dst: HuaweiTechno_1d:90:5a (a4:dc:be:1d:90:5a)
Destination: HuaweiTechno_1d:90:5a (a4:dc:be:1d:90:5a)
.... ..0. .... .... .... .... = LG bit: Globally unique address (factory default)
.... ...0 .... .... .... .... = IG bit: Individual address (unicast)
Source: HuaweiTechno_c2:aa:95 (10:24:07:c2:aa:95)
.... ..0. .... .... .... .... = LG bit: Globally unique address (factory default)
.... ...0 .... .... .... .... = IG bit: Individual address (unicast)
Type: IPv4 (0x0800)
[Stream index: 0]
Internet Protocol Version 4, Src: 172.30.17.80, Dst: 172.30.53.4
Transmission Control Protocol, Src Port: 102, Dst Port: 58240, Seq: 41852036, Ack: 56555347, Len: 27
TPKT, Version: 3, Length: 27
ISO 8073/X.224 COTP Connection-Oriented Transport Protocol
S7 Communication
Header: (Ack_Data)
Parameter: (Write Var)
Data
Item [1]: (Success)
Return code: Success (0xff)
Item [2]: (Success)
Return code: Success (0xff)
Item [3]: (Success)
Return code: Success (0xff)
Item [4]: (Success)
Return code: Success (0xff)
Item [5]: (Success)
Return code: Success (0xff)
Item [6]: (Success)
Return code: Success (0xff)`

[minterjiang]

    /// <summary>
    /// 处理IO请求的循环，从IO队列中读取请求并执行读写操作
    /// </summary>
    /// <param name="token"></param>
    /// <returns></returns>
    protected override async Task IoLoopAsync(CancellationToken token)
    {
        await foreach (var req in _ioChannel.Reader.ReadAllAsync(token))
        {
            try
            {
                if (!_isConnected || !_isOnline)
                {
                    req.Tcs?.SetException(new Exception("PLC离线"));
                    continue;
                }
                switch (req.Type)
                {
                    case PlcRequestType.Read:
                        var task = Task.Run(() => _s7Client.ReadMultipleVars(req.DataItems));
                        if (await Task.WhenAny(task, Task.Delay(_config.Timeout)) != task)
                        {
                            throw new TimeoutException("PLC读取超时");
                        }
                        req.Tcs?.TrySetResult(req.DataItems);
                        break;

                    case PlcRequestType.Write:
                        await _s7Client.WriteAsync(req.DataItems.ToArray());
                        _baseLogger.Debug($"写入 {req.DataItems.Count} 个数据项: {string.Join(",", req.DataItems.Select(d => d.Value))}");
                        req.Tcs?.TrySetResult(true);
                        break;
                }
            }
            catch (Exception ex)
            {
                req.Tcs?.TrySetException(ex);
                _baseLogger.Error(ex, $"IO执行失败: {req.Desc}");
            }
        }
    }