Set Up Information
Please download the User and Controller Manual.
If you don’t have Windows’s HyperTerminal program, Click Here to download the installation files.
If you use non-SMAC cables please refer to SMAC Actuator Manual (page 11) for advice on shielding and grounding.
Installation and Operation
If the actuator is in a vertical plane without a return spring fitted, the rod will drop if power to the unit is lost. Users must be aware of this as it may damage the end effecter being used and also will affect Emergency Stop procedures and re-set sequences.
Position Mode: Position Mode will allow the actuating rod to be moved to chosen positions along the stroke using acceleration, velocity and force. It is possible to make absolute, relative and "learned position" moves.
Velocity Mode: Velocity Mode allows the actuating rod to be moved with a given velocity, acceleration, force and direction. Typically used for Soft-Land routines.
Force Mode: Force Mode is open loop, using no feedback from the controller. Actual position can still monitored, but has no effect upon the output.
Duty Cycle: SMAC requires that all units must be operated at less than 40% maximum duty cycle. Duty cycle can be calculated as follows:
% of max force applied x % of cycle time it is applied = % duty cycle
100% force x 40% of cycle time = 40% duty
60% force x 50% of cycle time = 30% duty
40% force x 100% of cycle time = 40% duty
Recommendations from SMAC are that this duty cycle must not be exceeded over a one second time period.
NOTE: Failure to observe this duty cycle recommendation will usually result in the actuator sustaining damage through overloading. Overloading will overheat the coil and may cause it to deform and touch on the magnet housing.
If the actuator is in vertical plane with no spring return, it will use a certain amount of power just to hold its position. If the payload is excessive, this alone could be enough to exceed the duty cycle.
Laws of physics state that: Force = Mass x Acceleration
The actuator has a low moving mass, therefore with constant force applied and no load, a large acceleration will result. This will drive the rod into the end-stop on the actuator and may cause damage if it is repeatedly done.
The actuator is a precision piece of equipment in terms of both force and position. Alignment of the linear axis components must be maintained to ensure smooth running of the rod. To ensure it remains functioning in the correct manner, it is advisable to follow the guidelines.
Shaft Run Out: Shaft run out is typically <50 micron.
Resolution and Repeatability: Resolution, when applied to SMAC products, is defined as the smallest position increment produced by the encoder. Our standard encoder resolution is five microns, although most actuators also have the option to be fitted with a one micron or half micron encoder. Repeatability, sometimes referred to as reproducibility, is the ability of a system to return to a given position with little or no deviation. One of SMAC's principle advantages is the absence of any mechanical backlash which is inherent in so many stepper and ballscrew systems. In addition, our encoder reads the true linear position rather than converting the stepper motors rotary encoder signal to the linear ballscrew movement. With correct PID tuning, our actuators are repeatable to two encoder counts.
Controller Reporting and QA Functions: The controllers can output pass/fail and product performance figures, which can then be used in statistical QA and production analysis.