KUKA E93DA113I4B531伺服模块,KSD1-32使用教程
COMMREQ梯形图指令有四个输入和一个输出：COMMREQ梯形图指令启用输入：必须为逻辑1才能启用COMMREQ指令。建议：启用逻辑是过渡（“一次”）线圈的触点。IN：命令块第一个字的内存位置。它可以是任何有效的字型内存中的地址（%R、%AI或%AQ）。例如，%R00100 at IN将指示命令块的起始地址为%R00100。SYSID：一个十六进制值，给出所需模块的机架和插槽位置COMMREQ正在定位。
KUKA E93DA113I4B531伺服模块高位字节（十六进制数的前两位）包含机架号，低字节包含插槽号。下表显示了一些SYSID示例：当激活COMMREQ梯形图指令时，启动通信请求在PLC扫描期间。此时，来自PLC的命令通过通信请求发送至PROFIBUS主模块（PBM）。在每个请求结束时，PLC CPU将请求的状态报告给状态字，是PLC内存中由状态字指定的位置命令块中的指针。在上图中，PBM显示在CPU机架中，通信发生在PLC背板。如果PBM位于扩展机架或远程机架中，则命令数据通过扩展电缆或远程电缆通过CPU机架的背板发送连接到包含PBM的机架，并穿过该机架的背板连接到PBM。 COMMREQ指令应通过过渡线圈的触点启用。
如果在梯形图程序中使用多个COMMREQ，请验证之前的COMMREQ在执行另一个命令之前已成功执行。这是可以做到的通过检查状态字和FT（故障）输出。
如果启用输入未激活，则FT输出保持为假。这意味着如果COMMREQ由一个过渡（单次）触点启用，当故障发生时，FT仅一次PLC扫描的输出高。为了捕捉故障发生的事实，您需要可以将故障输出编程为设定线圈，在扫描结束。然后需要额外的逻辑来重置故障输出线圈
确认故障后，在下一次执行COMMREQ之前。
The COMMREQ ladder
instruction has four inputs and one
output:
Figure 4-1. COMMREQ Ladder Instruction
Enable Input: Must be Logic 1 to enable the COMMREQ Instruction. It is recommended that
the enabling logic be a contact from a transition (“one-shot”) coil.
IN: The memory location of the first word of the Command Block. It can be any valid
address in word-type memory (%R, %AI, or %AQ). For example, %R00100 at IN would
indicate that the starting address of the Command Block is %R00100.
SYSID: A hexadecimal value that gives the rack and slot location of the module that the
COMMREQ is targeting. The high byte (first two digits of the hex number) contains the
rack number, and the low byte contains the slot number. The table below shows some
examples of SYSIDs:A Communications Request is initiated when a COMMREQ ladder instruction is activated
during the PLC scan. At this time, a command from the PLC via the Communications
Request is sent to the PROFIBUS Master module (PBM).
At the conclusion of every request, the PLC CPU reports the status of the request to the
Status Word, which is a location in PLC memory that is designated by the Status Word
Pointer in the Command Block.
In the figure above, the PBM is shown in the CPU rack and communications occur over
the PLC backplane. If the PBM is located in an expansion or remote rack, the commands
and data are sent over the CPU rack’s backplane, through the expansion or remote cable
to the rack containing the PBM, and across that rack’s backplane to the PBM. COMMREQ instructions should be enabled by a contact from a transition coil.
