S72402-NANANA KOLLMORGEN伺服驱动器
伺服驱动器在用户程序执行阶段,PLC总是按由 上而下的顺序依次地扫描用户程序(梯形图)。在扫描每一条梯形图时, 又总是先扫描梯形图左边的由各触点构成的控制线路,并按先左后右、先上后下的顺序对由触点构成的控制线路进行逻辑运算,然后根据逻辑运算的结果,刷新该逻辑线圈在系统RAM存储区中对应位的状态;或者刷新该输出线圈在I/O映象区中对应位的状态;或者确定是否要执行该梯形图所规定的特殊功能指令。即,在用户程序执行过程中,只有输入点在I/O映象区内的状态和数据不会发生变化,而其他输出点和软设备在I/O映象区或系统RA存储区内的状态和数据都有可能发生变化,而且排在上面的梯形图,其程序执行结果会对排在下面的凡是用到这些线圈或数据的梯形图起作用;相反,排在下面的梯形图,其被刷新的逻辑线圈的状态或数据只能到下一个扫描周期才能对排在其上面的程序起作用。
S72402-NANANA KOLLMORGEN伺服驱动器
Servo driver in the user program execution stage, PLC always scans the user program in order from top to bottom (ladder diagram). When scanning each ladder diagram, always scan the control circuit composed of contacts on the left side of the ladder diagram first, and perform logical operation on the control circuit composed of contacts in the order of first left and then right, first up and then down, and then refresh the state of the corresponding bit of the logic coil in the system RAM storage area according to the result of logical operation; Or refresh that state of the corresponding bit of the output coil in the I/O map area; Or determine whether to execute the special function instruction specified in the ladder diagram. That is, in the process of user program execution, only the state and data of the input point in the I/O image area will not change, while the state and data of other output points and soft devices in the I/O image area or the system RA storage area may change, and the program execution result of the ladder diagram ranked above will play a role in the ladder diagram ranked below that uses these coils or data; On the contrary, in the ladder diagram arranged below, the status or data of the refreshed logic coil can only work on the program arranged above it in the next scanning cycle.
S72402-NANANA KOLLMORGEN伺服驱动器
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