IS220PDIAH1A燃机卡件
解释COMREQ状态字在解释COMREQ的内容时，需要记住以下几点：
状态字：1.以十六进制形式显示状态字，以便更容易区分高和低字节。这样做的一个好方法是使用“移动单词”功能块来显示梯形图程序中的十六进制值。
2.FIP总线控制器永远不会向PLC CPU。在发出
COMREQ函数，然后检查非零值，表明FIP总线控制器正在响应COMREQ。这样做的一个好方法是使用移动字功能块将COMREQ状态字归零。
3.低字节中的状态码1和高字节中的0表示请求是成功的。所有其他非零值表示错误。有关主要和次要错误代码的完整列表，请参阅附录B中的表格。开发控制COMREQ执行的逻辑时必须小心
作用每个梯形图计划，无论是在开发阶段还是在运行阶段
阶段，应在启动COMREQ功能之前执行以下操作。在下面例如，昵称用于使程序更易于遵循。
示例逻辑说明了这些要点：
1.使用单触发过渡线圈或触点启动COMREQ功能。这防止多次发送相同的COMREQ命令块。
2.在总线控制器状态字中至少包括总线控制器OK位作为COMREQ功能的联锁触点。您可以添加更多的联锁。
3.将COMREQ状态（CRS）字以及OK和FT的字位置归零启动COMREQ之前COMREQ功能块的输出。
4.将COMREQ的命令代码和参数移动到存储器中COMREQ功能块输入中指定的位置，在COMREQ之前
启动功能。在示例逻辑中：第1级：输入FIPIFOK（FIP总线控制器状态位的第16位）监控FIP
总线控制器。如果可以发送COMREQ，则健康线圈打开。健康用作梯级3-6的联锁装置。
横档#2：输入BEGREAD触发READREQ，从而执行移动以及COMREQ功能。READREQ是一个单触发线圈，在BEGREAD时激活一次从关闭转换为打开。
Interpreting the COMREQ Status Word
There are several points to remember when interpreting the contents of the COMREQ
Status word:
1. Display the Status Words in hexadecimal form to more easily differentiate the high and
low bytes. A good way to do this is to use a MOVE WORD function block to display
the hexadecimal value within the ladder program.
2. The FIP Bus Controller will never send a zero for the COMREQ Status Word to the
PLC CPU. The program should zero the COMREQ Status word before issuing the
COMREQ function and then check for a non-zero value indicating that the FIP Bus
Controller is responding to the COMREQ. A good way to do this is to use a MOVE
WORD function block to zero the COMREQ Status Word.
3. A status code of 1 in the low byte and 0 in the high byte indicates that the request
was successful. All other non-zero values indicate errors. Refer to the tables in Appendix B for a complete listing of major and minor error codes.Care must be taken in developing the logic that controls the execution of the COMREQ
function. Every ladder program, whether in the developmental phase or the operational
phase, should do the following before initiating a COMREQ function. In the following
example, Nicknames are used to make the program easier to follow.The example logic illustrates these important points:
1. Initiate the COMREQ function with a one-shot transitional coil or contact. This
prevents sending the same COMREQ Command Block more than once.
2. Include at least the Bus Controller OK bit in the Bus Controller Status Word as an
interlock contact for the COMREQ function. You may add more interlocks.
3. Zero the word location for the COMREQ Status (CRS) word, and OK and FT
Outputs of the COMREQ Function Block before initiating the COMREQ.
4. Move the command code and parameters for the COMREQ into the memory
location specified in IN input of the COMREQ Function Block before the COMREQ
function is initiated.
In the example logic:
Rung # 1: Input FIPIFOK (bit 16 of the FIP Bus Controller Status bits) monitors the FIP
Bus Controller. If it is OK to send a COMREQ, the HEALTHY coil is ON. HEALTHY is
used as an interlock for Rungs 3-6.
Rung # 2: Input BEGREAD triggers READREQ, which enables execution of the MOVE
and COMREQ functions. READREQ is a one-shot coil, activating once when BEGREAD
transitions from OFF to ON.
