订购热线：《DCS培训教材》
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As a rule, the data transmitted via I/O terminals handled by the regulatory control blocks must be the engineering unit data. Each data item consists of data value and data status.作为一个准则，经过I/O端子传输给调整控制块的数据必须是工程单位型的数据。每个数据项应包括数据值和数据状态。
■ Data Value 数据值SAI533-H03/PRP
The data value is a numeric data that is transmitted in or out of a function block. The data values handled by the blocks include process variable (PV), cascade setpoint value (CSV) and manipulated output value (MV).数据值是在一个功能块内或外进行传输的一个数字的数据。这种被功能块所处理的数值可以包括过程变量，串级设定值和操作输出值SAI533-H03/PRP。
The data values handled by the regulatory control blocks are numeric data in engineering unit. However, the data received from the input modules (excluding the input modules for temperature measurement as well as for pulse trains) and the setpoint data sent to analogue output modules are given as percentage values in the range from 0% to 100%.调整控制块处理的数值必须是带工程单位的数字值。数据被输入模块接收（温度测量和脉冲串的输入模块除外），然后设定值被发送到模拟输出模块，形式为0％到100％的百分数值。
The data value read into a function block via an input terminal is called “input data,” while the value written out of a function block via an output terminal is called “output data.” 经由输入端子读入功能块的数据值叫做输入数据，而由输出端子从功能块写出的值叫做输出数据SAI533-H03/PRP。
■ Data Status 数据状态
The data status is a piece of status information that indicates the value and quality of I/O data. 数据状态是指出输入输出数据值和性质的一块状态信息。
The data status is conveyed as I/O data from one function block to another via I/O connection along with a data value.数据状态都会伴随一个数据值，从而作为输入输出数据通过I/O连接器从一个功能块传到另一个功能块SAI533-H03/PRP。
The data status is used to test the existence of exceptional events, such as process failures and computation errors occurred in the control computation processing performed by the function blocks.数据状态用于检测例外事件的发生，比如功能块执行控制计算处理中的过程故障，计算错误SAI533-H03/PRP。
SEE ALSO参考
For the details of data status, see a chapter C6, “Block Mode and Status.”
关于数据状态的详细介绍，请见C6“Block mode and Status.”
