"# modbus_build_request\u51fd\u6570\u539f\u578b\n\n> 2023-02-13 | 2023-02-13\n> https:\/\/www.modbus.cn\/en\/11787.html\n\n**Modbus\u7f16\u7a0b\u5f00\u53d1**\n\n---\n\nmodbus_build_request\u51fd\u6570\u662flibmodbus\u5e93\u4e2d\u7684\u4e00\u4e2a\u51fd\u6570\uff0c\u5176\u539f\u578b\u4e3a\uff1a\n\nint modbus_build_request(modbus_t *ctx, int function, int addr, int nb, uint8_t *req);\n\n\u5176\u4e2d\uff0c\u53c2\u6570\u542b\u4e49\u5982\u4e0b\uff1a\n\n- `ctx`\uff1a\u6307\u5411modbus_t\u7ed3\u6784\u4f53\u7684\u6307\u9488\uff0c\u8868\u793a\u4f7f\u7528\u54ea\u4e2aModbus\u4e0a\u4e0b\u6587\u5bf9\u8c61\u3002\n\n- `function`\uff1a\u8868\u793a\u8bf7\u6c42\u7684Modbus\u51fd\u6570\u7801\u3002\n\n- `addr`\uff1a\u8868\u793a\u8bf7\u6c42\u7684\u5bc4\u5b58\u5668\u5730\u5740\u3002\n\n- `nb`\uff1a\u8868\u793a\u8bf7\u6c42\u7684\u5bc4\u5b58\u5668\u6570\u91cf\u3002\n\n- `req`\uff1a\u8868\u793a\u5b58\u50a8\u8bf7\u6c42\u6570\u636e\u7684\u7f13\u51b2\u533a\u3002\n\n\u51fd\u6570\u8fd4\u56de\u503c\u4e3a\u8bf7\u6c42\u6570\u636e\u7684\u957f\u5ea6\uff0c\u5982\u679c\u8fd4\u56de\u503c\u5c0f\u4e8e0\uff0c\u5219\u8868\u793a\u51fa\u9519\u3002\n\n\u8be5\u51fd\u6570\u7528\u4e8e\u6784\u9020Modbus\u8bf7\u6c42\u62a5\u6587\uff0c\u5c06\u62a5\u6587\u6570\u636e\u5b58\u50a8\u5728\u7f13\u51b2\u533a\u4e2d\uff0c\u53ef\u4ee5\u901a\u8fc7\u8c03\u7528\u51fd\u6570\u5c06\u8bf7\u6c42\u62a5\u6587\u53d1\u9001\u51fa\u53bb\u3002\u5728\u6784\u9020\u8bf7\u6c42\u62a5\u6587\u65f6\uff0c\u53c2\u6570\u6307\u5b9a\u8bf7\u6c42\u7684Modbus\u51fd\u6570\u7801\uff0c\u53c2\u6570\u6307\u5b9a\u8bf7\u6c42\u7684\u5bc4\u5b58\u5668\u5730\u5740\uff0c\u53c2\u6570\u6307\u5b9a\u8bf7\u6c42\u7684\u5bc4\u5b58\u5668\u6570\u91cf\uff0c\u53c2\u6570\u4e3a\u5b58\u50a8\u8bf7\u6c42\u6570\u636e\u7684\u7f13\u51b2\u533a\u3002`req``modbus_send_raw_request``function``addr``nb``req`\n\n---\n*modbus.cn*\n"