ctx = modbus_new_tcp("127.0.0.1", 1502);<\/pre><\/div>\n\n\n\n2. \u6620\u5c04 Modbus \u6570\u636e\u6a21\u578b<\/h3>\n\n\n\n
\u63a5\u4e0b\u6765\uff0c\u6211\u4eec\u9700\u8981\u5b9a\u4e49\u670d\u52a1\u5668\u5c06\u8981\u4f7f\u7528\u7684 Modbus \u6570\u636e\u6620\u5c04\u3002\u8fd9\u4e00\u6b65\u9aa4\u662f\u901a\u8fc7 modbus_mapping_new<\/code> \u51fd\u6570\u5b8c\u6210\u7684\uff0c\u5b83\u4e3a\u4e0d\u540c\u7c7b\u578b\u7684 Modbus \u6570\u636e\uff08\u4f4d\u3001\u8f93\u5165\u4f4d\u3001\u4fdd\u6301\u5bc4\u5b58\u5668\u548c\u8f93\u5165\u5bc4\u5b58\u5668\uff09\u5206\u914d\u548c\u521d\u59cb\u5316\u5185\u5b58\uff1a<\/p>\n\n\n\nmb_mapping = modbus_mapping_new(500, 500, 500, 500);\nif (mb_mapping == NULL) {\n fprintf(stderr, "Failed to allocate the mapping: %s\\n", modbus_strerror(errno));\n modbus_free(ctx);\n return -1;\n}<\/pre><\/div>\n\n\n\n3. \u76d1\u542c\u548c\u63a5\u53d7\u5ba2\u6237\u7aef\u8fde\u63a5<\/h3>\n\n\n\n
\u4e00\u65e6\u6570\u636e\u6620\u5c04\u51c6\u5907\u597d\uff0c\u670d\u52a1\u5668\u5c31\u53ef\u4ee5\u5f00\u59cb\u76d1\u542c\u6765\u81ea\u5ba2\u6237\u7aef\u7684\u8fde\u63a5\u8bf7\u6c42\u3002\u4f7f\u7528 modbus_tcp_listen<\/code> \u51fd\u6570\u5f00\u59cb\u76d1\u542c\uff0c\u7136\u540e\u4f7f\u7528 modbus_tcp_accept<\/code> \u5904\u7406\u63a5\u5165\u7684\u5ba2\u6237\u7aef\u8fde\u63a5\uff1a<\/p>\n\n\n\ns = modbus_tcp_listen(ctx, 1);\nmodbus_tcp_accept(ctx, &s);<\/pre><\/div>\n\n\n\n4. \u63a5\u6536\u548c\u54cd\u5e94\u8bf7\u6c42<\/h3>\n\n\n\n
\u670d\u52a1\u5668\u7684\u4e3b\u5faa\u73af\u5305\u62ec\u7b49\u5f85\u5ba2\u6237\u7aef\u8bf7\u6c42\u3001\u63a5\u6536\u8bf7\u6c42\u3001\u5904\u7406\u8bf7\u6c42\uff0c\u5e76\u53d1\u9001\u54cd\u5e94\u3002\u8fd9\u901a\u8fc7\u4e0d\u65ad\u8c03\u7528 modbus_receive<\/code> \u51fd\u6570\u6765\u63a5\u6536\u8bf7\u6c42\uff0c\u5e76\u4f7f\u7528 modbus_reply<\/code> \u51fd\u6570\u6765\u53d1\u9001\u54cd\u5e94\uff1a<\/p>\n\n\n\nfor (;;) {\n rc = modbus_receive(ctx, query);\n if (rc > 0) {\n modbus_reply(ctx, query, rc, mb_mapping);\n } else if (rc == -1) {\n break;\n }\n}<\/pre><\/div>\n\n\n\n5. \u6e05\u7406\u548c\u5173\u95ed\u8d44\u6e90<\/h3>\n\n\n\n
\u4e00\u65e6\u670d\u52a1\u5668\u5b8c\u6210\u4efb\u52a1\uff08\u901a\u5e38\u662f\u7531\u4e8e\u9519\u8bef\u6216\u5ba2\u6237\u7aef\u5173\u95ed\u8fde\u63a5\uff09\uff0c\u5b83\u9700\u8981\u91ca\u653e\u6240\u6709\u5206\u914d\u7684\u8d44\u6e90\uff0c\u5e76\u4f18\u96c5\u5730\u5173\u95ed\u8fde\u63a5\uff1a<\/p>\n\n\n\n
printf("Quit the loop: %s\\n", modbus_strerror(errno));\nif (s != -1) {\n close(s);\n}\nmodbus_mapping_free(mb_mapping);\nmodbus_close(ctx);\nmodbus_free(ctx);<\/pre><\/div>\n\n\n\n\u901a\u8fc7\u4e0a\u8ff0\u6b65\u9aa4\uff0c\u6211\u4eec\u5c55\u793a\u4e86\u5982\u4f55\u4f7f\u7528 libmodbus \u521b\u5efa\u4e00\u4e2a\u529f\u80fd\u5b8c\u5907\u7684 Modbus TCP \u670d\u52a1\u5668\u3002\u8fd9\u4e2a\u670d\u52a1\u5668\u80fd\u591f\u5904\u7406\u6807\u51c6\u7684 Modbus \u529f\u80fd\u7801\uff0c\u5305\u62ec\u8bfb\u5199\u5355\u4e2a\u6216\u591a\u4e2a\u4f4d\u548c\u5bc4\u5b58\u5668\u7684\u64cd\u4f5c\u3002\u672c\u793a\u4f8b\u4e0d\u4ec5\u9002\u7528\u4e8e\u6559\u80b2\u548c\u6d4b\u8bd5\u76ee\u7684\uff0c\u4e5f\u53ef\u4ee5\u4f5c\u4e3a\u5b9e\u9645\u5e94\u7528\u4e2d\u7684\u57fa\u7840\u3002<\/p>\n<\/span>","protected":false},"excerpt":{"rendered":"\u5728\u73b0\u4ee3\u5de5\u4e1a\u901a\u4fe1\u4e2d\uff0cModbus \u534f\u8bae\u56e0\u5176\u7b80\u6d01\u6027\u548c\u6613\u4e8e\u5b9e\u73b0\u800c\u88ab…<\/p>","protected":false},"author":1,"featured_media":27977,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":"","_members_access_role":[],"_members_access_error":""},"categories":[691],"tags":[695,694,690,237],"class_list":["post-27716","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-modbus-code-base","tag-include","tag-libmodbus","tag-modbus-protocol","tag-tcp"],"_links":{"self":[{"href":"https:\/\/www.modbus.cn\/en\/wp-json\/wp\/v2\/posts\/27716","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.modbus.cn\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.modbus.cn\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.modbus.cn\/en\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.modbus.cn\/en\/wp-json\/wp\/v2\/comments?post=27716"}],"version-history":[{"count":0,"href":"https:\/\/www.modbus.cn\/en\/wp-json\/wp\/v2\/posts\/27716\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.modbus.cn\/en\/wp-json\/wp\/v2\/media\/27977"}],"wp:attachment":[{"href":"https:\/\/www.modbus.cn\/en\/wp-json\/wp\/v2\/media?parent=27716"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.modbus.cn\/en\/wp-json\/wp\/v2\/categories?post=27716"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.modbus.cn\/en\/wp-json\/wp\/v2\/tags?post=27716"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}