Introduction to DeviceNet Cable Limitations When Calculating DeviceNet Cable Limitations, it’s important to realize that we cannot exceed a 4.65 volt drop. Basically, we just use Ohms Law to calculate this voltage drop. There is some important information we need before we begin our calculation. First, we need to know Read More »
Introduction to the ControlLogix FOR Instruction The ControlLogix FOR Instruction allows us to execute a routine for a specific number of times. To understand how a FOR loop works, let’s go back and look at some examples of BASIC from 1975. In this example, we will print the value of Read More »
Introduction to Relocating Array Data in ControlLogix In this post, we’ll be Relocating Array Data in ControlLogix by one element. For example, if we have a fault log, we might want to move all of the array data down one element. Our newest data will be at element zero. It’s Read More »
Introduction to the ControlLogix Average Instruction (AVE) The ControlLogix Average Instruction (AVE) will find the average of a file. The file will simply be a group of numeric tags within an array. For example, we can use the AVE instruction to smooth out a noisy process variable to find the Read More »
Introduction to ControlLogix Clock Calibration Today, I wanted to discuss the ControlLogix Clock Calibration. Actually, that is a little bit misleading though, because we can’t really calibrate the clock itself. We can adjust it each day though. One way to do this is through the clock update tool. Another method Read More »
Introduction to Wiring any Logic using only NAND Gates I’ve heard people say before that you can hard wire any logic using only NAND Gates. I started researching this a little bit, and purchased some NAND gate IC’s (74HC00). In this post, we’ll see how we would wire AND, OR, Read More »
Introduction to the ControlLogix Watch Window The ControlLogix Watch Window allows you to monitor tags from the current routine. You can also create a custom “Quick Watch” window to monitor any tag in the processor as you monitor the routine’s latter logic. This is very helpful when troubleshooting. Especially when Read More »
Introduction to ControlLogix Processor Status Flags ControlLogix Processor Status Flags will tell us when certain events occur during our instruction execution. In this section, we’ll discuss the purpose of each of these status flags, and how we might use them in our logic. It’s important to realize that you will Read More »
Resolving ControlLogix I/O Not Responding If you have ControlLogix I/O Not Responding, you will have a blinking green I/O light on the processor. Additionally, while you are online, you will see “I/O Not Responding” in the online toolbar. The newer processors have an alphanumeric display which could give you some Read More »
Solving when a ControlLogix Rung is True but No Output It’s frustrating when a ControlLogix Rung True but you have No Output. In this section we’ll go over the causes for this, and how to correct them. It’s important that the processor is just doing what it’s told. We just Read More »
