Productivity PLC Motion - How To Use The Built-in High Speed Test Tool from AutomationDirect

Suppose you have a Productivity Series Controller with a High Speed Output Module driving a stepper drive which is controlling a stepper motor and the motor isn’t reacting to the commands you are sending it from the ladder code in the controller. With so many active components in the chain, where do you start when the motor doesn’t react to commands sent from the ladder code? Is it your code? Or is it one of the electronic components? Debugging problems like this can be time consuming and expensive. The good news is the Productivity Suite software has a tool that makes debugging this stuff so easy. Let’s setup a new project. Choose a CPU – we’re using the one connected to the USB port. This CPU is brand new it has NO project in it. With the CPU in STOP mode, go to system configuration and auto detect all the hardware. Double click on that and we see we have a Productivity 2000 controller with two high speed output cards in it’s base, one in slot 1 and one in slot 2. Great, we selected a CPU and auto-detected the hardware. We have NO code in the CPU and we haven’t configured the HSO modules. We’ve just detected the hardware. That’s it. Given that, check this out – Under the tools menu there is a high speed module testing tool. It’s also over here under Monitor and Debug. This tool gives me complete control over the HSO module and it is completely independent of the ladder code in the controller and the Module’s configuration – neither of which we have done yet! Here are my two modules, the one in slot 1 and the one in slot 2. Let’s test the slot 1 module. To do that click on Start Monitoring. The module has two high speed output channels. I have a motor connected to channel 1 so we’ll play with that one. My drive is set to 2000 pulses per revolution so if we send 20,000 pulses per second the slides screw should turn 10 times per second. And since the screws pitch is .5 inches per revolution, we’ll expect to see 5 inches of travel per second. Let’s accelerate and decelerate at twice that rate. This system is wired for pulse and direction and I have the carriage in the center of the slide so I don’t care which direction we start with. Now if I hit START I instantly see the carriage ramp up to speed and move at 5 inches per second. Perfect. And remember – we did all of this completely independent of any PLC code or High Speed Output Module configuration. So if the motor does move as expected, we know our issue is back here. If the motor doesn’t move – the issue is over here. This tool just cut the scope of our debug problem in half and tells us exactly where we need to be focusing our attention – hardware or software. And since we have absolute control over the pulses generated, we can also use it to verify we have the stepper drive configured correctly. And by playing with this I can instantly see that “Positive” direction means the slide moves to the right and “Negative” Direction is to the left. Another time saver - I don’t have to figure it out – I just try it and see the answer. What happens if I put zero acceleration in here? Nothing! Why? Because we told it NOT to ramp up to speed! Makes sense- right? What happens if we put a low value in for acceleration – well it takes forever to ramp up to speed. The stop button will ramp down at the deceleration rate and Abort stops everything dead in its tracks - immediately. The beauty of this tool is you can play with the motion system and get a feel for how it is going to react to commands all BEFORE you write your first line of ladder code or even configure the module. So now when you DO write your Ladder Code you know exactly what to expect and you know you have functioning hardware. And that makes your life so much easier. Also note that since the HSO modules always maintain real time position and real time velocity information independent of the processor, you can see those actual values while you are testing. You can also monitor all the HSO Modules discrete inputs and even manipulate all the outputs. Again, Independent of the code in the processor. So the bottom line is this tool gives you complete control over the entire HSO module independent of the rest of the project so you can setup and test your hardware before writing your first line of code which makes you more productive. Which is why we call it the “Productivity” family of controllers. If you need any help, please contact Automation Direct’s free award winning support team during regular business hours. They will be happy to help. And don’t forget the forums. There are lots of folks there that love to share their years of experience. Just don’t post any questions directed at AutomationDirect’s support team there – they don’t monitor the forums on a regular basis.