EtherCAT:EC SDO READ STRING/zh-hans
< EtherCAT:EC SDO READ STRING
Revision as of 17:12, 6 May 2017 by Chi (talk | contribs) (Created page with "{{Languages}} == 描述 == 与EC_SDO_READ类似, 此功能允许读取STRING值。<br/> 要从从站读取数据，我们必须指定一个SDO索引...")
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描述
与EC_SDO_READ类似, 此功能允许读取STRING值。
要从从站读取数据，我们必须指定一个SDO索引和一个子索引。
第一个子索引为0.如果只存在一个子索引，我们还需要指定0（我们不能忽略该字段）。
读取值从函数返回，可以设置为变量。
输入
Slave address, SDO index, SDO sub-index.
输出
str_length - 该输出变量由字符串长度的函数填充
返回值
从从站中读取的字符串。
声明
public function EC_SDO_READ_STRING(byval slaveaddres as long, byval index as long, byval subindex as long, str_length as long) as string
格式
retVal = EC_SDO_READ_STRING(<Slave address>, <SDO index>, <SDO sub-index>, <String's length>)
例外
EC_SLAVE_ADDRESS_ERROR - "SLAVE ADDRESS ERROR" 20032
EC_SDO_READ_WRITE_ONLY - "SDO READ ERROR: Attempt to read a write-only object" 20060
EC_SDO_READ_SIZE - "SDO READ ERROR: Received an unreasonable amount of data" 20064
例子
ret_Str = EC_SDO_READ_STRING(module_address, 0x6000, 1, length)