DirectLOGIC PLC Motion Control with SureStep Stepper (Part 1 of 8) from AutomationDirect

Hi, Tom with AutomationDirect here. In the following series of videos I will be using the SureStep Stepping System to cover the topic of Motion Control. The Stepping System will be controlled by a DirectLOGIC PLC through a High-Speed Counter Interface module that I’ve installed. A C-more Micro-Graphic panel, used as my operator interface, will be connected to the PLC. Let’s get started with a short description of the videos in the series, and a rundown of the SureStep product lineup. This Motion Control video series will include eight videos. I have broken the series down into topics that will allow you the opportunity to either view the entire series from start to finish, or just view the topics that are relevant to your needs. The SureStep Stepping System drive I have chosen to use in my demonstration is typically commanded by a string of pulses representing the motor’s rotary position, and also a rotary directional signal. In my case I will obtain these signals from a High-Speed Counter Interface module, AutomationDirect’s part number H0-CTRIO, which is plugged into an expansion slot of a DirectLOGIC DL05 Micro Programmable Logic Controller that I will be using. I will use a C-more Micro-Graphic panel as my human to machine interface, typically abbreviated HMI, also called an operator interface. The C-more panel will communicate to the PLC and allow me to select the motion profile that I want executed. I will mechanically couple a SureStep stepping motor to a linear lead screw slide as part of my demonstration. The stepper motor’s rotary motion will be converted to a linear motion through the lead screw, and by controlling how many steps the stepping motor indexes, I will be able to control the linear travel of the slide to an accurate position. More details on this to follow. Keep in mind that there is a companion Power Point handout that can be downloaded as a PDF file from the learn.automationdirect.com Web site, and be used to follow along with the videos. It is also useful as a future refresher to what it takes to create a working Motion Control System. Let me also point out that throughout the video series I have included short cut links to technical information that is available on AutomationDirect’s Web site. See the example here. To summarize the topics within the video series; I will briefly cover ‘What is Motion Control?’, explain various methods that are used for controlling stepping systems, and also cover the hardware I have selected for my demonstration. I will then cover the component wiring, setting up the hardware jumpers for the High-Speed Counter Interface module, and include the DIP switch settings for the SureStep Stepping Motor Drive. Up next I cover the programming, which I have separated into three videos. The first programming video covers all of the setup and programming of the High-Speed Counter Interface module using the CTRIO Workbench utility software. The second programming video covers the PLC programming using the DirectSOFT 5 software for my ladder logic and IBox instructions, which are a great time saver. The third programming video gets me into my C-more operator interface programming. In the final video I demonstrate the linear slide motion profiles. If you get a chance take a look at the two part Tech Thread article titled “Starting with Steppers” that was published in the Automation Notebook. You should find it useful as a reference to technical information available on stepping systems. Here are the short cut links. Part 1 covers the SureStep product and explains the various methods to control a stepping system by way of pulse and directional signals. Part 2 focuses on using ASCII commands through a serial communications port to provide motion profiles that are available from the Advanced Microstepping Drives. Look for future LEARN videos on Motion Control that cover using this feature. What is Motion Control? Motion Control, as used in industrial automation, is the task of controlling the position and/or velocity of an actuator, typically an electric motor. The actuator in many cases will be translated into linear positioning, although rotary position is also used. Motion Control can be found in applications ranging from robotics, to packaging, to pick and place type applications used in product assembly, and of course material handling equipment. It is helpful to understand that a Motion Control System typically consists of a controller that will generate the signals for the motion profile, a drive or amplifier to transform the motion signals into the proper high power electrical currents and voltages, an electrical motor that is driven by the drive that can create the mechanical motions, and some form of a mechanical device, such as a gearbox, rack and pinion, or pulleys and a belt, that translates the motor’s rotary motion into the final ‘work’ motion to be performed. With some motion control systems, such as a servo mechanism, a feedback sensor is used to return the final position signals back to the motion controller. This is commonly referred to as a closed-loop system. If there is no feedback sensor or signal, then we would refer to our motion control system as being open-loop. The motion control system I will use in my demonstration with the SureStep Stepping System is an open-loop type system, meaning there is no feedback, and I am relying on the stepper motor with the drive, to respond accurately to the number of pulses that my DL05 PLC with High-Speed Counter Interface module controller will produce. It may be helpful at this point for me to cover the SureStep Stepping System product family. Keep in mind that the SureStep open-loop stepping systems provide simple and accurate control of position and speed where lower power and cost are considerations. The current product line, as of the taping of this video series, consists of one DIP switch configurable micro-stepper drive, two software configurable advanced micro-stepper drives, four stepping motor power supplies, nine stepper motors, and two stepper motor extension cables. And we can’t forget the Free stepper configuration software that is used with the advanced drives! Keep an eye open for addition components to be added to the SureStep product line in the near future. The signals that are "translated" by the micro-stepping drives into precise movement of the stepper motor shaft can be provided by AutomationDirect’s family of PLCs, or other indexers and motion controllers. Next I’ll cover some additional information on the DIP switch configurable micro-stepper drive. This drive can accept an input voltage of 12 to 42 volts DC, and can produce a selectable current from 0.4 to 3.5 Amps, which is the stepper motor’s current rating per phase. I’ll be using the part number STP-DRV-4035 drive as part of my Motion Control demonstration, and will cover it in more detail in the Part 4 video titled “Wiring, CTRIO Jumper Settings & Drive DIP Switch Settings”. With a few DIP switch settings on the drive, wiring up a step motor, connecting to a controller, and applying power, we can have an operating stepping system in short order. Our latest stepper motor drives are the SureStep part number STP-DRV-4850 and part number STP-DRV-80100 Advanced Programmable stepper drives. The Advanced Programmable drives can be commanded with either pulse and directional signals, or ASCII commands from a serial communications port using the Serial Command Language. Using the Free SureStep Pro Configuration Software, the Advanced Programmable drives include selectable resolutions up to 51,200 steps per revolution for smoother, more accurate motion, and up to 10 Amps per phase power capability. Again, look for future LEARN videos on Motion Control that cover using the Advanced Programmable stepper drives with ASCII commands. Let’s look at the various stepper motors that are offered in the product lineup. The SureStep stepper motors use 2-phase technology with 200 full steps per revolution. There are currently nine standard motors that can handle a wide range of automation applications. The stepper motors include different torque ratings in NEMA motor sizes 17, 23 and 34. Available are two different 20 foot extension cables, with locking connectors, that can interface between the various stepper motors and stepper drives. The last items in our SureStep product lineup are the Stepping System Power Supplies. The stepper system will require power for both the stepper drive and stepper motor. Also the drive’s logic, along with the PLC or other device that provides the signals, require a power source. There are four models available with 32 Volts at 4 Amps, 48 Volts at 5 Amps, 48 Volts at 10 Amps, and 70 Volts at 5 Amps output, all unregulated DC, providing power to the stepper drive and motor. Each supply also has a 5 Volt DC plus or minus 5 percent at 500 milli-Amp regulated logic power, with electronic overload, that can be used with the drive’s logic circuitry. The power supplies are matched to the SureStep drives for maximum voltage. Join me in Part Two of this video series on Motion Control where I’ll cover the various methods for controlling a SureStep Stepping System.