无线模块设计了一个计数器，用于记录启动次数，放在 count.dat 文件中。

count.dat ASCII编码的纯文本文件，默认值一个字节：0

Air202/Air720SL-NP 读取：

startCountor = file:read("*n")            --读取返回 nil

startCountor = tonumber(file:read("*l"))  --读取正常

Air202写入：

file:write(startCountor)                  --写入正常

Air720SL-NP写入：

file:write(startCountor)                   --有写入错误，提示：desc=Exception - Branch to 0x0 detected

file:write(tostring(startCountor))         --无错误提示，但写不成功，内容没变

--2G Air202 模块启动次数计数
local startCountor = 0
local function StartCount()
    local file = io.open("/ldata/count.dat", "r")
    --startCountor = file:read("*n")           --file:read("n") 2G模块读取返回 nil
    startCountor = tonumber(file:read("*l"))  --这样读取就没问题了
    file:close()

    if startCountor == nil then
        startCountor = 0
    end
    if startCountor >= 2147483647 then  --最大的32位有符号整形数字：2147483647 = 0x7FFF FFFF
        startCountor = 0
    end

    file = io.open("/ldata/count.dat", "w")
    startCountor = startCountor + 1
    file:write(startCountor)
    file:close()
end

--4G Air720SL-NP 模块启动次数计数
local startCountor = 0
local function StartCount()
    local file = io.open("/lua/count.dat", "r")
	--startCountor = file:read("*n")           --file:read("n") 4G模块读取返回 nil
	startCountor = tonumber(file:read("*l"))  --这样读取就没问题了
    file:close()

    if startCountor == nil then
        startCountor = 0
    end
    if startCountor >= 2147483647 then  --最大的32位有符号整形数字：2147483647 = 0x7FFF FFFF
        startCountor = 0
    end

    file = io.open("/lua/count.dat", "w")
	startCountor = startCountor + 1
        --file:write(startCountor)          --file:write(startCountor) 4G 模块写错误提示：desc=Exception - Branch to 0x0 detected
	file:write(tostring(startCountor))  --无错误提示，但写不成功，内容没变
    file:close()
end