"# VisualHMI \u6587\u4ef6 IO\uff1aLUA \u8bfb\u5199 SD \u5361\/U \u76d8\/Flash \u4e0e\u76ee\u5f55\u5217\u4e3e\n\n> 2026-08-04 | 2026-08-04\n> http:\/\/www.modbus.cn\/en\/51508.html\n\n**LUA \u811a\u672c, \u4e32\u53e3\u5c4f\/HMI \u5f00\u53d1**\n\n---\n\nLUA \u652f\u6301\u8bfb\u5199 SD \u5361 \/ U \u76d8 \/ \u5185\u90e8 Flash \u6587\u4ef6\uff1a\u76ee\u5f55\u5217\u4e3e\u3001\u6253\u5f00\u3001\u8bfb\u3001\u5199\u3001\u5b9a\u4f4d\u3001\u5173\u6587\u4ef6\u3002\u9002\u5408\u914d\u65b9\u6587\u4ef6\u3001\u6570\u636e\u5bfc\u51fa\u3001\u65e5\u5fd7\u843d\u5730\u3002\n\n## 1. \u8def\u5f84\u4e0e\u76d8\u7b26\n\n\u7cfb\u5217SD\u5361U\u76d8\u5185\u90e8FlashM \u7cfb\u52171:2:3:DH \u7cfb\u5217\/sdcard\/udisk\/data\n\n![\u6587\u4ef6IO](https:\/\/www.modbus.cn\/wp-content\/uploads\/2026\/08\/visualhmi\/lu012_1.png)\n\n## 2. API\n\n\u51fd\u6570\u8bf4\u660elist_dir(path)\u5217\u4e3e\u76ee\u5f55\uff0c\u7ed3\u679c\u901a\u8fc7 on_list_dir \u9010\u6761\u56de\u8c03on_list_dir(path, filename, type, fsize)\u56de\u8c03\uff1atype 0=\u6587\u4ef6\u5939\/1=\u6587\u4ef6\uff0cfsize \u6587\u4ef6\u5927\u5c0ffile_open(path, mode)\u6253\u5f00\u6587\u4ef6\uff1amode 0=FA_READ\uff08\u8bfb\uff09\/1=FA_WRITE\uff08\u8986\u76d6\u5199\uff09\/2=FA_WRITE_ADD\uff08\u8ffd\u52a0\uff09file_close()\u5173\u95ed\u5f53\u524d\u6587\u4ef6file_size()\u5f53\u524d\u6587\u4ef6\u5b57\u8282\u6570file_seek(offset)\u5b9a\u4f4d\u8bfb\u5199\u4f4d\u7f6efile_read(count)\u8bfb count \u5b57\u8282\uff081~2048\uff09\uff0c\u8fd4\u56de\u4e0b\u6807\u4ece 1 \u7684\u5b57\u8282\u8868file_write(data)\u5199\u6570\u636e\n\n## 3. \u6848\u4f8b\uff1aSD \u5361\u76ee\u5f55\u5217\u8868\n\n```\nfunction on_init()\n  list_dir(\"1:\/music\")   -- \u5217SD\u5361music\u76ee\u5f55\nend\n\nfunction on_list_dir(path, filename, type, fsize)\n  if type == 1 then  -- \u6587\u4ef6\n    print(path .. filename .. \" \" .. fsize .. \"B\")\n  end\nend\n```\n\n## 4. \u6848\u4f8b\uff1a\u8bfb\u6587\u4ef6\uff08\u6d41\u5f0f\u5904\u7406\uff09\n\n```\nfunction read_file_ok()\n  file_open(\"1:\/data\/recipe.txt\", 0)  -- \u8bfb\u6a21\u5f0f\n  local remain = file_size()\n  local line = \"\"\n  while remain > 0 do\n    local n = (remain > 64) and 64 or remain\n    local buf = file_read(n)          -- \u6bcf\u6b21\u6700\u591a2048, \u5efa\u8bae\u5c0f\u5757\n    -- \u5904\u7406 buf...\n    remain = remain - n\n  end\n  file_close()\nend\n```\n\n![\u6587\u4ef6\u8bfb\u5199](https:\/\/www.modbus.cn\/wp-content\/uploads\/2026\/08\/visualhmi\/lu012_2.png)\n\n\u6587\u4ef6 IO \u6700\u5bb9\u6613\u8e29\u5185\u5b58\u6ea2\u51fa\u7684\u5751\uff1a**\u4e25\u7981\u5168\u5c40\u7d2f\u8ba1\u5927\u7f13\u51b2\u2014\u2014\u6bcf\u6b21 file_read \u540e\u7acb\u5373\u89e3\u6790\u91ca\u653e\uff0c\u5fc5\u987b\u6d41\u5f0f\u5904\u7406\uff0c\u5426\u5219\u5185\u5b58\u6ea2\u51fa\u89e6\u53d1\u770b\u95e8\u72d7\u590d\u4f4d**\u3002\u5199 SD \u5361\u6ce8\u610f\u6587\u4ef6\u5df2\u5b58\u5728\u65f6 mode=2 \u8ffd\u52a0\u3001mode=1 \u8986\u76d6\u3002\n\n\u6574\u7406\u81ea \u5e7f\u5dde\u5927\u5f69\u79d1\u6280 VisualHMI \u5f00\u53d1\u6587\u6863\uff08hmi-doc.gz-dc.com\uff09LUA \u6559\u7a0b\u300c\u6587\u4ef6IO\u300d\uff0c\u7248\u6743\u5f52\u5927\u5f69\u79d1\u6280\u6240\u6709\u3002\n\n---\n*modbus.cn*\n"