336A4940CSP11汽轮机模块
COMREQ命令块包含有关要使用的特定命令的信息执行。当COMREQ功能启动时，命令块从PLC CPU连接到FIP总线控制器。使用适当的编程指令设置命令块（建议使用块移动功能块）。命令块具有以下结构：s字指针偏移量字5保留
字6保留
字7至128（十进制）数据块（FIP命令详细信息）
（字1）数据块长度：这是命令块（最多122个十进制字）。数据块部分从字7开始
命令块。长度从数据块的开始处开始测量字7，而不是从命令块的开始。
（字2）WAIT/NOWAIT标志：对于所有FIP通信，该标志必须设置为零。
（字3）COMREQ状态字指针内存类型：该字指定内存
t可监控COMREQ状态字，以确定故障原因
COMREQ功能启动后出现通信错误。的位置
COMREQ状态字在COMREQ功能的命令块中定义。
执行COMREQ后，如果COMREQ状态字不是一（1），则表明：成功意味着：命令块中的错误，或对于建立读或写FIP命令，命令参数有效
但在建立信道时出现了错误
如果COMREQ状态字不包含表示成功的1，则它包含0或代码（见下文）指示发生了什么错误。每次扫描时，CPU中不更新COMREQ状态字。总线控制器
如果命令阻塞，立即向CPU返回COMREQ状态字
包含语法错误，或者如果命令是本地的（例如，中止通道和检索详细的信道状态命令）。PLC之间发生通信
CPU和FIP总线控制器。对于这些命令，COMREQ状态字
立即发送到CPU。对于没有语法错误的远程命令，它是在通道成功建立且第一次传输完成后返回已完成，或者在建立信道时出现错误。
The COMREQ Command Block contains information about the specific command to be
executed. When the COMREQ function is initiated, the Command Block is sent from
the PLC CPU to the FIP Bus Controller. The Command Block is set up using an appropriate programming instruction (the BLOCK MOVE Function Block is recommended). The Command Block has the following structure:s Word Pointer Offset
Word 5 Reserved
Word 6 Reserved
Words 7 up to 128 (decimal) Data Block (FIP command details)
(Word 1) Data Block Length: This is the length in words of the Data Block portion of the
Command Block (up to 122 words-decimal). The Data Block portion starts at Word 7 of
the Command Block. The length is measured from the beginning of the Data Block at
Word 7, not from the beginning of the Command Block.
(Word 2) WAIT/NOWAIT Flag: This flag must be set to zero for all FIP communications.
(Word 3) COMREQ Status Word Pointer Memory Type: This word specifies the memory
tThe COMREQ Status word can be monitored to determine the cause of a
communications error after the COMREQ function is initiated. The location of the
COMREQ status word is defined in the Command Block for the COMREQ function.
After executing a COMREQ if the COMREQ Status Word is not one (1) indicating
success, it means that there were:
Errors in the Command Block or
For an Establish Read or Write FIP command, the command parameters were valid
but there was an error in establishing a channel.
If the COMREQ Status Word does not contain a 1 indicating success, then it contains
either a 0 or a code (see below) indicating what error occurred.The COMREQ Status word is not updated in the CPU each scan. The Bus Controller
returns the COMREQ Status word to the CPU immediately if the Command Block
contains a syntax error or if the command is local (for example, the Abort Channel and
Retrieve Detailed Channel Status commands). Communication occurs between the PLC
CPU and the FIP Bus Controller only. For these commands, the COMREQ Status word
is sent immediately to the CPU. For remote commands with no syntax error, it is
returned either after the channel is established successfully and the first transfer has
completed or if there is an error establishing the channel.
