In this lesson we will describe the difference between modifying addresses and forcing them. This lesson discusses what happens with either of these functions when the PLC power is turned off or when you are connected with your computer and you disconnect. The force function has an external indicator on the PLC which the modify does not. This is a quick indication when troubleshooting a program that something may be forced. The modify function has no indication when in use. Open up this lesson to give you a recap of the modify and force functions.
In previous lessons we have discussed the Process Image Input or PII and its purpose. In this lesson we discuss the size of the PII and what will be required of you to know, as the programmer, when it comes to being able to access your I/O when the boundary of the PII is exceeded. Each PLC has a ...
In the previous lesson we discussed the Process Image Input or PII and its size. We wrote a simple move instruction to access an analog input only to find that just as soon as we downloaded it to the PLC, the PLC faulted and went into stop mode. In this lesson we will discuss the PII further and ...
In previous lessons we discussed the Process Image Input or PII, its purpose, size, and what happens when exceeded. We wrote a simple move instruction to demonstrate the PII boundary and faulted the PLC, diagnosed that fault, and found out how we need to handle our I/O when our PII boundary is ex...
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