回复:关于FM350-1，没人说得很明白-技术论坛-工业支持中心-西门子中国

回复:关于FM350-1，没人说得很明白

dcount107

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普通如何晋级?

发布于 2009-06-19 12:53:42

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LDIRECT是直接写技术值，L_PREPAR只是将LOAD_VAL写到preparation预置值中，那么预置值什么时候写入计数值？手册上有一段话：
You can load the load value in preparation only (control signal L_PREPAR). A load
value that is loaded in preparation is accepted by the FM 350-1 as a new counter
value in response to the following events:
In the single counting and periodic counting Count modes
– When the upper or lower limit is reached if no main counting direction is set.
– When the set upper counting limit is reached for main counting direction up.
– When 0 is reached for main counting direction down.
In all Count modes
– The counting process is started by the interrupting SW or HW gate (the load
value is not accepted when the counting continues).
– Synchronization
– Latch/retrigger

非淡泊无以明志，非宁静无以致远