Automated Process Control Applications
Manufacturing Automation Services provides the highest quality Test and Measurement solutions for your automated manufacturing system.
Applications that require a dedicated processing resource to be able to reliably respond to events, or output a response
precisely after an input event is detected can benefit from a real-time system. For example, a monitoring system on an oil
rig will need to respond to alarm conditions reliably in order to prevent damage. A PC based application may not be reliable
enough in this scenario because the general purpose operating system of the PC may be servicing other task during an alarm event.
Real-Time controllers will provide deterministic loop rates, that is, events are guaranteed to occur on a specific clock pulse. Also, all real-time controllers will have a known clock jitter (which can be very small) allowing for the application to compensate if necessary. Standard PC operation systems are inherently non-deterministic and do not have well defined clock jitter specifications.
Programmable Logic Controllers are real-time targets that are specifically designed to handle multiple inputs and outputs. They have extended operating temperatures and are suitable for electrically noisy environments. Inputs to, and outputs from a PLC are used to monitor and control various processes. PLC’s are flexible and can be reprogrammed to control other systems. Ladder logic is the main programming method used for PLCs.
Motion systems are made up of 3 major components, motors, motor drives and motor controllers. A motor can be attached to a variety of mechanical devices, such as linear slides, rotary stages, etc, and is responsible for moving something. The motor can be categorized as either a stepper or servo and each provide unique benefits. The choice is dependent on the application that it will be used for. Stepper motors are typically used for low speed and low cost applications. Servos are used in higher speeds, varying torque, and industrial applications. The motor drive provides the proper power required to operate the motor. Finally, the motor controller is the brain behind a motion profile. Feedback signals, especially for servo motors, are read by the motor controller to determine motor characteristics such as position, speed, and torque. These input signals allow the controller to make the proper output adjustments in order to maintain a predetermined motion profile.
Vision systems are comprised of lens, lighting, camera, and a processing system. Processing can be performed on a variety of different platforms, such as a standard PC, a Real-Time system or even on the camera itself. Vision systems can be used in a manufacturing environment where they, for example, help to detect product defects, or assist in sorting components. There are many commercially available off-the-shelf vision algorithms that can assist vision processing automation.
Pneumatic systems use pressurized gas to produce a simple mechanical action rather than an electrical motor. Most factory environments have a compressed inert gas plumbed throughout the floor and therefore pneumatic systems can be cost effective. Controlling a pneumatic actuator, for example, only requires a simple on-off (digital) command. Pneumatic systems will generally have a long operating life and little maintenance compared to traditional electrical or hydraulic systems.
Time critical operations need to execute on a specific schedule to function as desired. These time critical operations cannot handle delays in execution. For example, hardware I/O that has a specified timing needs to execute exactly when expected. Therefore for time critical operations, a real-time operating system is used so that all resources are dedicated in executing the application. These operating systems have the ability to reliably respond to an event or perform an operation within a specified time period.