In this lesson, I'm going to replace this three position selector switch with a two position switch and then revise the software such that there won't be any change in the way that the machine operates. This means that with the new two position selector switch, I will be able to change the machine operation mode from manual to automatic and vice versa just as I could with the three position selector switch.
The number of S7 counters you can use in your program depends on the model of the CPU you're using in your project. How can you find out how many S7 counters you can use or what happens if you enter an out of range address in the software? These are what you'll learn after watching this lesson.
When you're using counters in your PLC program, if the PLC goes into the stop mode or the power cuts off, you'll lose all of the counter values and these values cannot be restored after running the PLC again.
There are some programming tools and setups in the "STEP 7" that can be used to protec...
Previously, you learned that you can use S7 timers for the purpose timing in your programs. The maximum time value you can have for these timers is 2 hours and 46 minutes. But in some projects you may need longer time values. One way to increase the time value for timing is to use a combination o...
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