{"id":103786,"date":"2026-09-11T10:09:25","date_gmt":"2026-09-11T02:09:25","guid":{"rendered":"https:\/\/www.wsisp.com\/helps\/103786.html"},"modified":"2026-09-11T10:09:25","modified_gmt":"2026-09-11T02:09:25","slug":"modbus%e6%9c%8d%e5%8a%a1%e7%ab%af%e5%ae%9e%e7%8e%b0_%e8%99%9a%e6%8b%9fplc","status":"publish","type":"post","link":"https:\/\/www.wsisp.com\/helps\/103786.html","title":{"rendered":"Modbus\u670d\u52a1\u7aef\u5b9e\u73b0_\u865a\u62dfPLC"},"content":{"rendered":"

PLCMonitor \u5185\u7f6e Modbus TCP \u670d\u52a1\u7aef：\u8ba9\u7b2c\u4e09\u65b9 SCADA \u96f6\u6539\u9020\u5bf9\u63a5<\/h2>\n

\u628a PLCMonitor \u53d8\u6210\u4e00\u53f0"\u865a\u62df PLC"，\u5916\u90e8 WinCC \/ \u89e6\u6478\u5c4f \/ \u80fd\u8017\u7f51\u5173\u76f4\u63a5\u7528 Modbus \u8bfb\u6570\u636e\u3002libmodbus \u5728 Windows UCRT64 \u4e0b\u7684\u5751\u3001\u8d8a\u754c\u8bfb\u7684\u6392\u67e5\u9ed1\u6d1e\u3001\u5bc4\u5b58\u5668\u6620\u5c04\u5730\u5740\u7ea6\u5b9a，\u5168\u90e8\u8bf4\u6e05\u695a\u3002<\/p>\n

\n

\u80cc\u666f：\u4e3a\u4ec0\u4e48\u8981\u505a Modbus \u670d\u52a1\u7aef？<\/h3>\n

PLCMonitor \u672c\u8eab\u5df2\u7ecf\u901a\u8fc7 S7 \/ Modbus TCP Client \/ OPC UA \u7b49\u534f\u8bae\u91c7\u96c6\u4e86\u73b0\u573a\u6570\u636e\u3002\u4f46\u73b0\u573a\u8fd8\u6709\u53e6\u4e00\u7c7b\u7cfb\u7edf\u4e5f\u9700\u8981\u8fd9\u4e9b\u6570\u636e\u2014\u2014\u80fd\u8017\u7ba1\u7406\u5e73\u53f0\u3001\u7b2c\u4e09\u65b9 HMI\u3001\u697c\u5b87\u81ea\u63a7\u7cfb\u7edf\u2026\u2026\u8ba9\u5b83\u4eec\u91cd\u65b0\u63a5\u4e00\u904d PLC \u901a\u8baf\u6808\u6210\u672c\u592a\u9ad8\u3002<\/p>\n

Modbus TCP \u662f\u5de5\u4e1a\u9886\u57df\u6700\u666e\u53ca\u7684\u534f\u8bae，\u51e0\u4e4e\u6240\u6709 SCADA \/ HMI \u90fd\u652f\u6301\u3002\u5982\u679c PLCMonitor \u81ea\u5df1\u5c31\u662f\u4e00\u4e2a Modbus Server，\u7b2c\u4e09\u65b9\u7cfb\u7edf\u76f4\u63a5\u914d\u7f6e\u5730\u5740\u548c\u7aef\u53e3\u5c31\u80fd\u8bfb\u5230\u6570\u636e，\u96f6\u6539\u9020\u3002<\/p>\n

\n

\u4e00\u3001\u7ebf\u7a0b\u6a21\u578b：N+1 \u8fde\u63a5\u7ebf\u7a0b，\u65e0\u9501\u70ed\u8def\u5f84<\/h3>\n

libmodbus \u7684\u4e0a\u4e0b\u6587（modbus_t）\u4e0d\u662f\u7ebf\u7a0b\u5b89\u5168\u7684，\u6bcf\u4e2a\u8fde\u63a5\u5fc5\u987b\u7528\u72ec\u7acb\u7684 ctx + mapping\u3002<\/p>\n

PLCMonitor \u7684\u505a\u6cd5：<\/p>\n

accept \u7ebf\u7a0b（\u4e3b\u7ebf\u7a0b\u521b\u5efa，\u963b\u585e\u5728 modbus_tcp_listen \u4e0a）
\n \u2502
\n \u2502 onClientAccepted(fd, peerIp) \u2190 QueuedConnection，\u4e3b\u7ebf\u7a0b\u89e6\u53d1
\n \u25bc
\n\u4e3b\u7ebf\u7a0b \u2500\u2500\u2192 QThread::create(connWorker, params) \u2190 \u6bcf\u8fde\u63a5\u4e00\u7ebf\u7a0b
\n \u251c\u2500 \u6301\u6709\u72ec\u7acb\u7684 modbus_t* ctx
\n \u251c\u2500 \u6301\u6709\u72ec\u7acb\u7684 modbus_mapping_t* mapping
\n \u2514\u2500 indication_timeout = 100ms（stop \u540e 100ms \u5185\u9000\u51fa）<\/p>\n

\u5173\u952e\u7ea6\u675f：\u6240\u6709 QThread \u5bf9\u8c61\u90fd\u5728\u4e3b\u7ebf\u7a0b\u521b\u5efa，\u7ebf\u7a0b\u4eb2\u548c\u6027\u4e3a\u4e3b\u7ebf\u7a0b，deleteLater() \u624d\u6709\u6548\u3002\u5de5\u4f5c\u7ebf\u7a0b\u7edd\u4e0d\u76f4\u63a5 emit \u6216\u8c03\u7528\u4e3b\u7ebf\u7a0b\u5bf9\u8c61，\u7edf\u4e00\u8d70 postMessage() \/ QMetaObject::invokeMethod(…, Qt::QueuedConnection)，\u4ee5\u4e3b\u7ebf\u7a0b\u7684 m_controller \u4e3a context\u3002<\/p>\n

\n

\u4e8c\u3001\u5bc4\u5b58\u5668\u6620\u5c04：\u6807\u7b7e\u5730\u5740 \u2192 PDU \u504f\u79fb<\/h3>\n

\u5730\u5740\u7ea6\u5b9a（\u5bf9\u9f50\u5de5\u4e1a\u4e3b\u6d41）<\/h4>\n\n\u6982\u5ff5\u503c\u8bf4\u660e<\/tr>\n\n\n\n\n\n
addr（\u6807\u7b7e\u5730\u5740）<\/td>\n40001, 40002, \u2026<\/td>\n\u534f\u8bae\u6807\u7b7e\u5730\u5740，4xxxx \u8303\u56f4<\/td>\n<\/tr>\n
offset（PDU \u504f\u79fb）<\/td>\n0, 1, \u2026<\/td>\noffset = addr – 40001<\/td>\n<\/tr>\n
holdStart（\u5bc4\u5b58\u5668\u8868\u57fa\u5740）<\/td>\n\u6052\u4e3a 0<\/td>\n\u5bc4\u5b58\u5668\u8868\u4ece PDU 0 \u8d77<\/td>\n<\/tr>\n
holdNb<\/td>\nmaxEnd + 1<\/td>\n\u5bc4\u5b58\u5668\u603b\u6570<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

\u8bbe\u8ba1\u610f\u56fe：\u7b2c\u4e09\u65b9\u7ec4\u6001\u9ed8\u8ba4\u4ece 40001 \u5f00\u59cb\u586b\u5730\u5740，holdStart=0 + offset = addr – 40001 \u7684\u6362\u7b97\u8ba9 40001 \u76f4\u63a5\u547d\u4e2d PDU 0，\u7528\u6237\u96f6\u601d\u8003\u5373\u53ef\u8fde\u901a\u3002<\/p>\n

buildTemplate \u6d41\u7a0b<\/h4>\n

\/\/ \u904d\u5386\u914d\u7f6e\u4e2d\u7684 mappings，\u6784\u5efa MappingTemplate<\/span>
\nfor<\/span> (<\/span>const<\/span> ModbusMappingEntry &<\/span>m :<\/span> cfg.<\/span>mappings)<\/span> {<\/span>
\n if<\/span> (<\/span>!<\/span>ModbusHelper<\/span>::<\/span>isHoldingRegisterLabel<\/span>(<\/span>m.<\/span>addr)<\/span>)<\/span> {<\/span>
\n \/\/ \u975e\u6cd5\u5730\u5740（\u975e 40001\u201349999 \/ 400001\u2013465536）\u2192 WARN \u8df3\u8fc7<\/span>
\n continue<\/span>;<\/span>
\n }<\/span>
\n MbMappingEntry e;<\/span>
\n e.<\/span>tagKey =<\/span> m.<\/span>tag;<\/span>
\n e.<\/span>addr =<\/span> m.<\/span>addr;<\/span>
\n e.<\/span>offset =<\/span> ModbusHelper<\/span>::<\/span>protocolAddressToOffset<\/span>(<\/span>m.<\/span>addr)<\/span>;<\/span> \/\/ addr – 40001<\/span>
\n \/\/ \u7c7b\u578b\u3001\u5b57\u8282\u5e8f\u3001scale \u89e3\u6790…<\/span>
\n t-><\/span>addrToIndex.<\/span>insert<\/span>(<\/span>e.<\/span>offset,<\/span> t-><\/span>entries.<\/span>size<\/span>(<\/span>)<\/span>)<\/span>;<\/span>
\n t-><\/span>entries.<\/span>append<\/span>(<\/span>e)<\/span>;<\/span>
\n maxEnd =<\/span> qMax<\/span>(<\/span>maxEnd,<\/span> e.<\/span>offset +<\/span> e.<\/span>regCount –<\/span> 1<\/span>)<\/span>;<\/span>
\n}<\/span>
\nt-><\/span>holdStart =<\/span> 0<\/span>;<\/span>
\nt-><\/span>holdNb =<\/span> qMax<\/span>(<\/span>1<\/span>,<\/span> maxEnd +<\/span> 1<\/span>)<\/span>;<\/span> \/\/ \u81f3\u5c11 1，\u9632\u6b62 libmodbus \u5206\u914d NULL<\/span><\/p>\n

\u7a7a\u6d1e\u884c\u4e3a：\u57fa\u5740\u5230\u9996\u4e2a\u6620\u5c04\u4e4b\u95f4\u7684 PDU \u504f\u79fb\u8bfb\u56de 0（\u4e0d\u662f\u5f02\u5e38\u7801 02）\u3002\u8fd9\u662f libmodbus \u5bc4\u5b58\u5668\u8868\u521d\u59cb\u5316\u7684\u81ea\u7136\u7ed3\u679c，\u5b9e\u6d4b holdNb=12 \u65f6 PDU 0\/8\/10\/11 \u6210\u529f\u3001PDU 12 \u624d\u56de 02\u3002<\/p>\n

\n

\u4e09\u3001\u4e00\u4e2a\u9690\u85cf\u5751：\u76d1\u542c fd \u6cc4\u6f0f\u5bfc\u81f4\u65ad\u8fde\u540e\u65e0\u6cd5\u91cd\u8fde<\/h3>\n

\u75c7\u72b6<\/h4>\n

\u4fee\u6539 Modbus \u914d\u7f6e \u2192 \u505c\u7528 \u2192 \u542f\u7528，\u7aef\u53e3\u4ecd\u663e\u793a 502，\u9762\u677f\u663e\u793a"\u8fd0\u884c\u4e2d"，\u4f46\u65b0\u5ba2\u6237\u7aef connect \u6210\u529f\u5374\u65e0\u6cd5\u6536\u5230\u54cd\u5e94\u3002\u53ea\u80fd\u91cd\u542f\u5e94\u7528\u3002<\/p>\n

\u6839\u56e0（libmodbus \u6e90\u7801，\u4e0d\u662f\u731c\u6d4b）<\/h4>\n

\/\/ libmodbus modbus-tcp.c: modbus_tcp_listen()<\/span>
\n\/\/ \u81ea\u5efa socket \u76f4\u63a5 return new_s，\u4ece\u4e0d\u5199\u56de ctx->s<\/span>
\nctx-><\/span>s =<\/span> –<\/span>1<\/span>;<\/span> \/\/ _modbus_init_common \u7f6e -1<\/span>
\n\/\/ … \u521b\u5efa socket，bind，listen …<\/span>
\nreturn<\/span> new_s;<\/span> \/\/ \u2190 \u6ca1\u6709 ctx->s = new_s！<\/span><\/p>\n

\u800c modbus_close() \u5185\u90e8：<\/p>\n

\/\/ _modbus_tcp_close()<\/span>
\nif<\/span> (<\/span>ctx-><\/span>s >=<\/span> 0<\/span>)<\/span> {<\/span> \/\/ ctx->s \u4ecd\u662f -1 \u2192 \u6761\u4ef6\u4e0d\u6210\u7acb<\/span>
\n closesocket<\/span>(<\/span>ctx-><\/span>s)<\/span>;<\/span>
\n}<\/span><\/p>\n

\u7ed3\u679c：stop() \u8c03\u7528 modbus_close(m_listenCtx) \u662f\u7a7a\u64cd\u4f5c，\u76d1\u542c socket \u6cc4\u6f0f\u4f46\u7aef\u53e3\u4ecd\u88ab\u5360\u7528\u3002<\/p>\n

Windows \u673a\u5236（\u63a2\u9488\u5b9e\u6d4b）：SO_REUSEADDR \u5141\u8bb8\u540c\u7aef\u53e3\u4e24\u4e2a\u6d3b\u8dc3\u76d1\u542c socket \u5171\u5b58，\u4f46\u65b0\u8fde\u63a5\u5f52"\u5148\u6ce8\u518c"\u7684\u90a3\u4e2a\u3002\u6cc4\u6f0f\u7684\u5b64\u513f socket \u5403\u6389\u5168\u90e8\u65b0\u8fde\u63a5，\u65b0 accept \u7ebf\u7a0b\u6c38\u8fdc\u6536\u4e0d\u5230\u3002<\/p>\n

\u4fee\u590d<\/h4>\n

\/\/ listenOnce() \u91cc\u8865\u4e00\u884c：modbus_set_socket \u56de\u586b ctx->s<\/span>
\nint<\/span> fd =<\/span> modbus_tcp_listen<\/span>(<\/span>ctx,<\/span> 0<\/span>)<\/span>;<\/span>
\nmodbus_set_socket<\/span>(<\/span>ctx,<\/span> fd)<\/span>;<\/span> \/\/ \u2190 \u8865\u8fd9\u4e00\u884c<\/span>
\nm_listenFd =<\/span> fd;<\/span><\/p>\n

\/\/ stop() \u515c\u5e95：modbus_get_socket() < 0 \u65f6\u76f4\u63a5 closeFd<\/span>
\nif<\/span> (<\/span>modbus_get_socket<\/span>(<\/span>m_listenCtx)<\/span> <<\/span> 0<\/span>)<\/span> {<\/span>
\n closeFd<\/span>(<\/span>m_listenFd)<\/span>;<\/span>
\n m_listenFd =<\/span> –<\/span>1<\/span>;<\/span>
\n}<\/span><\/p>\n

\n

\u56db\u3001\u8d8a\u754c\u8bfb：libmodbus \u4e0d\u56de\u8c03\u5e94\u7528\u5c42，\u53ea\u80fd\u8bf7\u6c42\u524d\u9884\u5224<\/h3>\n

libmodbus \u7684 modbus_reply() \u5bf9\u8d8a\u754c\u8bfb\u9759\u9ed8\u56de\u5f02\u5e38\u7801 02（Illegal Data Address），\u4e0d\u56de\u8c03\u5e94\u7528\u5c42，\u670d\u52a1\u7aef\u65e5\u5fd7\u91cc\u5b8c\u5168\u6ca1\u6709\u75d5\u8ff9\u3002\u7528 mbpoll \u6d4b\u8bd5\u65f6\u53ea\u4f1a\u770b\u5230 02 Illegal Data Address，\u5374\u4e0d\u77e5\u9053\u4e3a\u4ec0\u4e48\u3002<\/p>\n

PLCMonitor \u7684\u505a\u6cd5：\u5728 modbus_reply() \u4e4b\u524d\u624b\u52a8\u9884\u5224：<\/p>\n

void<\/span> logOutOfRangeRead<\/span>(<\/span>ConnParams &<\/span>p,<\/span> int<\/span> fc,<\/span> const<\/span> uint8_t<\/span> *<\/span>query,<\/span> int<\/span> rc)<\/span> {<\/span>
\n if<\/span> (<\/span>rc <<\/span> 12<\/span>)<\/span> return<\/span>;<\/span>
\n const<\/span> int<\/span> a =<\/span> (<\/span>query[<\/span>8<\/span>]<\/span> <<<\/span> 8<\/span>)<\/span> |<\/span> query[<\/span>9<\/span>]<\/span>;<\/span>
\n const<\/span> int<\/span> qty =<\/span> (<\/span>query[<\/span>10<\/span>]<\/span> <<<\/span> 8<\/span>)<\/span> |<\/span> query[<\/span>11<\/span>]<\/span>;<\/span>
\n const<\/span> int<\/span> lo =<\/span> p.<\/span>tmpl-><\/span>holdStart;<\/span>
\n const<\/span> int<\/span> hi =<\/span> p.<\/span>tmpl-><\/span>holdStart +<\/span> p.<\/span>tmpl-><\/span>holdNb –<\/span> 1<\/span>;<\/span>
\n if<\/span> (<\/span>a <<\/span> 0<\/span> ||<\/span> qty <<\/span> 1<\/span> ||<\/span> (<\/span>a >=<\/span> lo &&<\/span> a +<\/span> qty –<\/span> 1<\/span> <=<\/span> hi)<\/span>)<\/span> return<\/span>;<\/span><\/p>\n

\/\/ \u6bcf\u8fde\u63a5\u6bcf\u79d2\u6700\u591a\u4e00\u6761，\u907f\u514d mbpoll \u7c7b\u5de5\u5177 1s \u8f6e\u8be2\u65f6\u5237\u5c4f<\/span>
\n const<\/span> quint64 now =<\/span> QDateTime<\/span>::<\/span>currentMSecsSinceEpoch<\/span>(<\/span>)<\/span>;<\/span>
\n if<\/span> (<\/span>now –<\/span> p.<\/span>rangeLogMs >=<\/span> 1000<\/span>)<\/span> {<\/span>
\n qWarning<\/span>(<\/span>)<\/span> <<<\/span> "[Modbus]"<\/span> <<<\/span> p.<\/span>peerIp <<<\/span> "\u8bfb\u5730\u5740\u8d8a\u754c：\u8bf7\u6c42 PDU "<\/span>
\n <<<\/span> a <<<\/span> "\u00d7"<\/span> <<<\/span> qty <<<\/span> "，\u53ef\u8bfb\u533a\u95f4 ["<\/span> <<<\/span> lo <<<\/span> ","<\/span> <<<\/span> hi <<<\/span> "]"<\/span>;<\/span>
\n p.<\/span>rangeLogMs =<\/span> now;<\/span>
\n }<\/span> else<\/span> {<\/span>
\n ++<\/span>p.<\/span>rangeSuppressed;<\/span>
\n }<\/span>
\n \/\/ \u56de\u5305\u4ecd\u4ea4\u7ed9 modbus_reply()，\u4fdd\u6301\u6807\u51c6\u884c\u4e3a\u4e0d\u53d8<\/span>
\n}<\/span><\/p>\n

\n

\u4e94\u3001\u6570\u636e\u7c7b\u578b\u4e0e\u5b57\u8282\u5e8f<\/h3>\n

\u652f\u6301\u7684\u7c7b\u578b<\/h4>\n\n\u6807\u7b7e\u7c7b\u578b\u5bc4\u5b58\u5668\u6570\u8bf4\u660e<\/tr>\n\n\n\n\n\n\n
int16<\/td>\n1<\/td>\n\u6709\u7b26\u53f7 16 \u4f4d<\/td>\n<\/tr>\n
uint16<\/td>\n1<\/td>\n\u65e0\u7b26\u53f7 16 \u4f4d<\/td>\n<\/tr>\n
int32<\/td>\n2<\/td>\n\u6709\u7b26\u53f7 32 \u4f4d<\/td>\n<\/tr>\n
uint32<\/td>\n2<\/td>\n\u65e0\u7b26\u53f7 32 \u4f4d<\/td>\n<\/tr>\n
float32（\u9ed8\u8ba4）<\/td>\n2<\/td>\nIEEE 754 \u5355\u7cbe\u5ea6<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

\u5b57\u8282\u5e8f<\/h4>\n

4 \u79cd\u6392\u5217，\u5bf9\u5e94\u5de5\u4e1a\u5e38\u89c1\u89c4\u8303：<\/p>\n\n\u540d\u79f0\u5bc4\u5b58\u56680\u5bc4\u5b58\u56681\u8bf4\u660e<\/tr>\n\n\n\n\n\n
ABCD<\/td>\n\u6700\u9ad8\u5b57\u8282<\/td>\n\u6700\u4f4e\u5b57\u8282<\/td>\n\u5927\u7aef\u4f18\u5148<\/td>\n<\/tr>\n
BADC<\/td>\n\u4f4e\u5b57\u8282\u5728\u9ad8\u4f4d<\/td>\n\u2014<\/td>\n\u4ea4\u6362\u5bf9\u5185\u5b57\u8282<\/td>\n<\/tr>\n
CDAB（\u9ed8\u8ba4）<\/td>\n\u4f4e\u5b57\u5728\u524d<\/td>\n\u9ad8\u5b57\u5728\u540e<\/td>\n\u6700\u5e38\u89c1<\/td>\n<\/tr>\n
DCBA<\/td>\n\u6700\u4f4e\u5b57\u8282<\/td>\n\u6700\u9ad8\u5b57\u8282<\/td>\n\u5c0f\u7aef\u4f18\u5148<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

\u6240\u6709\u7f16\u89e3\u7801\u7edf\u4e00\u5230"ABCD \u89c4\u8303\u5b57\u8282"\u4e2d\u8f6c，\u5b57\u8282\u5e8f\u53ea\u5728\u5bc4\u5b58\u5668\u5c42\u6392\u5e03：<\/p>\n

void<\/span> valueToWireBytes<\/span>(<\/span>double<\/span> val,<\/span> ModbusType t,<\/span> uint8_t<\/span> b[<\/span>4<\/span>]<\/span>)<\/span> {<\/span>
\n \/\/ \u7edf\u4e00\u8f93\u51fa b[0]=\u6700\u9ad8\u5b57\u8282, b[3]=\u6700\u4f4e\u5b57\u8282<\/span>
\n \/\/ encodeIntoRegisters \u518d\u6309 ByteOrder \u6392\u5e03\u5230 regs[0]\/regs[1]<\/span>
\n}<\/span><\/p>\n

\n

\u516d\u3001\u6388\u6743\u95e8\u63a7<\/h3>\n

Modbus \u670d\u52a1\u7aef\u4e0d\u662f\u5e38\u5f00\u57fa\u7840\u8bbe\u65bd，\u53d7 License \u6a21\u5757\u63a7\u5236：<\/p>\n

    \n
  • .lic \u6587\u4ef6\u4e2d modules \u4e0d\u542b "modbus" \u2192 modbusServer()->start() \u4e0d\u8c03\u7528，\u7aef\u53e3\u5b8c\u5168\u4e0d\u76d1\u542c，\u63a7\u5236\u9762\u677f\u663e\u793a"\u672a\u6388\u6743"<\/li>\n
  • \u8bd5\u7528\u7248 \/ \u5df2\u6388\u6743 \u2192 \u6b63\u5e38\u542f\u52a8<\/li>\n<\/ul>\n

    \u8fd9\u4e0e\u5176\u4ed6\u5bf9\u5916\u63a5\u53e3（REST API\u3001MQTT）\u4fdd\u6301\u4e00\u81f4\u7684\u95e8\u63a7\u7b56\u7565\u3002<\/p>\n

    \n

    \u4e03\u3001\u5b9e\u9645\u5bf9\u63a5\u573a\u666f<\/h3>\n

    \u7b2c\u4e09\u65b9\u7cfb\u7edf\u914d\u7f6e\u793a\u4f8b（WinCC \/ \u89e6\u6478\u5c4f \/ \u80fd\u8017\u7f51\u5173）：<\/p>\n

    \u534f\u8bae： Modbus TCP
    \n\u5730\u5740： PLCMonitor \u6240\u5728\u673a\u5668\u7684 IP
    \n\u7aef\u53e3： 502
    \n\u7ad9\u53f7： 1（\u6216\u914d\u7f6e\u4e2d\u7684 unit_id）
    \n\u8bfb\u53d6\u5730\u5740：40001 \u8d77（\u5bf9\u5e94\u6807\u7b7e\u6620\u5c04\u7684\u7b2c\u4e00\u4e2a addr）<\/p>\n

    \u65e0\u9700\u5b89\u88c5\u989d\u5916\u9a71\u52a8，\u65e0\u9700\u6539 PLCMonitor \u4efb\u4f55\u4ee3\u7801，\u914d\u7f6e\u5373\u901a\u3002<\/p>\n

    \n

    \u603b\u7ed3<\/h3>\n\n\u8981\u70b9\u7ed3\u8bba<\/tr>\n\n\n\n\n\n\n\n
    \u7ebf\u7a0b\u6a21\u578b<\/td>\nN+1，\u6bcf\u8fde\u63a5\u72ec\u7acb ctx\/mapping，\u65e0\u9501\u70ed\u8def\u5f84<\/td>\n<\/tr>\n
    \u5730\u5740\u7ea6\u5b9a<\/td>\naddr=4xxxx，offset=addr-40001，holdStart=0<\/td>\n<\/tr>\n
    \u7a7a\u6d1e\u884c\u4e3a<\/td>\n\u672a\u6620\u5c04 PDU \u8bfb\u56de 0，\u4e0d\u62a5\u9519<\/td>\n<\/tr>\n
    \u76d1\u542c fd \u6cc4\u6f0f<\/td>\nlibmodbus \u4e0d\u5199\u56de ctx->s，\u9700\u624b\u52a8 modbus_set_socket \u56de\u586b<\/td>\n<\/tr>\n
    \u8d8a\u754c\u8bfb\u53ef\u89c2\u6d4b<\/td>\n\u8bf7\u6c42\u524d\u9884\u5224 + \u8282\u6d41\u65e5\u5fd7，modbus_reply() \u9759\u9ed8 02 \u65e0\u6cd5\u56de\u907f<\/td>\n<\/tr>\n
    \u5b57\u8282\u5e8f<\/td>\nABCD \/ BADC \/ CDAB（\u9ed8\u8ba4）\/ DCBA \u56db\u79cd，\u7edf\u4e00 byte array \u4e2d\u8f6c<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
    \n

    \u9879\u76ee\u5730\u5740：https:\/\/github.com\/freddiezhang1990\/plcmonitor<\/p>\n

    \u5982\u679c\u89c9\u5f97\u8fd9\u7bc7\u6587\u7ae0\u5bf9\u4f60\u6709\u5e2e\u52a9，\u6b22\u8fce\u70b9\u8d5e\u6536\u85cf，\u4e0b\u671f\u7ee7\u7eed\u5206\u4eab PLCMonitor \u7684\u5176\u4ed6\u8bbe\u8ba1\u5b9e\u8df5\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"

    PLCMonitor \u5185\u7f6e Modbus TCP \u670d\u52a1\u7aef：\u8ba9\u7b2c\u4e09\u65b9 SCADA \u96f6\u6539\u9020\u5bf9\u63a5 \u628a PLCMonitor \u53d8\u6210\u4e00\u53f0\\”\u865a\u62df PLC\\”，\u5916\u90e8 WinCC \/ \u89e6\u6478\u5c4f \/ \u80fd\u8017\u7f51\u5173\u76f4\u63a5\u7528 Modbus \u8bfb\u6570\u636e\u3002libmodbus \u5728 Windows UCRT64 \u4e0b\u7684\u5751\u3001\u8d8a\u754c\u8bfb\u7684\u6392\u67e5\u9ed1\u6d1e\u3001\u5bc4\u5b58\u5668\u6620\u5c04\u5730\u5740\u7ea6\u5b9a，\u5168\u90e8\u8bf4\u6e05\u695a\u3002 \u80cc\u666f：\u4e3a\u4ec0\u4e48\u8981\u505a Modbus \u670d\u52a1\u7aef？
    \nPLCMonitor \u672c\u8eab\u5df2\u7ecf\u901a\u8fc7 <\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[218,100,43,4647],"topic":[],"class_list":["post-103786","post","type-post","status-publish","format-standard","hentry","category-server","tag-qt","tag-100","tag-43","tag-4647"],"yoast_head":"\nModbus\u670d\u52a1\u7aef\u5b9e\u73b0_\u865a\u62dfPLC - \u7f51\u7855\u4e92\u8054\u5e2e\u52a9\u4e2d\u5fc3<\/title>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/www.wsisp.com\/helps\/103786.html\" \/>\n<meta property=\"og:locale\" content=\"zh_CN\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"Modbus\u670d\u52a1\u7aef\u5b9e\u73b0_\u865a\u62dfPLC - \u7f51\u7855\u4e92\u8054\u5e2e\u52a9\u4e2d\u5fc3\" \/>\n<meta property=\"og:description\" content=\"PLCMonitor \u5185\u7f6e Modbus TCP \u670d\u52a1\u7aef：\u8ba9\u7b2c\u4e09\u65b9 SCADA \u96f6\u6539\u9020\u5bf9\u63a5 \u628a PLCMonitor \u53d8\u6210\u4e00\u53f0"\u865a\u62df PLC"，\u5916\u90e8 WinCC \/ \u89e6\u6478\u5c4f \/ \u80fd\u8017\u7f51\u5173\u76f4\u63a5\u7528 Modbus \u8bfb\u6570\u636e\u3002libmodbus \u5728 Windows UCRT64 \u4e0b\u7684\u5751\u3001\u8d8a\u754c\u8bfb\u7684\u6392\u67e5\u9ed1\u6d1e\u3001\u5bc4\u5b58\u5668\u6620\u5c04\u5730\u5740\u7ea6\u5b9a，\u5168\u90e8\u8bf4\u6e05\u695a\u3002 \u80cc\u666f：\u4e3a\u4ec0\u4e48\u8981\u505a Modbus \u670d\u52a1\u7aef？ PLCMonitor \u672c\u8eab\u5df2\u7ecf\u901a\u8fc7\" \/>\n<meta property=\"og:url\" content=\"https:\/\/www.wsisp.com\/helps\/103786.html\" \/>\n<meta property=\"og:site_name\" content=\"\u7f51\u7855\u4e92\u8054\u5e2e\u52a9\u4e2d\u5fc3\" \/>\n<meta property=\"article:published_time\" content=\"2026-09-11T02:09:25+00:00\" \/>\n<meta name=\"author\" content=\"admin\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:label1\" content=\"\u4f5c\u8005\" \/>\n\t<meta name=\"twitter:data1\" content=\"admin\" \/>\n\t<meta name=\"twitter:label2\" content=\"\u9884\u8ba1\u9605\u8bfb\u65f6\u95f4\" \/>\n\t<meta name=\"twitter:data2\" content=\"3 \u5206\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\/\/schema.org\",\"@graph\":[{\"@type\":\"WebPage\",\"@id\":\"https:\/\/www.wsisp.com\/helps\/103786.html\",\"url\":\"https:\/\/www.wsisp.com\/helps\/103786.html\",\"name\":\"Modbus\u670d\u52a1\u7aef\u5b9e\u73b0_\u865a\u62dfPLC - 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