82 | Section 8 Glossary |
outside of it. The machine tool envelope can be disabled by clicking on the Clear Machine Zero button in Home mode.
Machine Zero - The origin (X,Y,Z = 0,0,0) of useful space within the machine tool envelope. Can either be defined manually or by using home switches.
Maximum Feedrate - The maximum rate at which a motor (or an axis) can reliably start and stop (with ramping).
Maximum Unramped Feedrate - The maximum rate at which a motor (or an axis) can reliably start and stop without ramping.
Modal - Modal commands stay in effect until another command in the same mode group is encountered.
Motor Polarity - The association between the actual direction an axis moves and the direction LC thinks it’s moving. If they are different, this value should be changed from positive to negative or
Motor Resolution - The number of full motor steps for one revolution of the motor. For example, a 1.8° Stepper motor will have 200 full steps per revolution, a 0.9° Stepper Motor will have 400 full steps per revolution, and so on.
Motor Step - The amount of movement associated with one electric pulse to the stepper motor. This will vary depending on the step mode and the steps per motor revolution.
Offline - Mode in which LC does not communicate with the Controller. (also called animation mode.) All
Online - Mode in which LC directly communicates with the Controller. In this mode, all G- Code, Jog and Point moves are executed by the machine tool.
Open Loop - A control system in which a device receives a command and executes the command without communicating back that the command was completed successfully. Most stepper motor systems are open loop due to there high reliability in performing step commands when used within their torque limits for a given RPM.
Part Program - Program used to control the movement of the machine tool.
Program Coordinates - The XYZ position of the tool on the CNC machine relative to Program Zero.
Program Listing Box - The area of the main screen that shows a listing of the part program currently loaded in LC.
Program Zero - The zero point, or origin, to which all absolute coordinates in the
Radio Buttons - A group of options requiring a single selection, like the channel buttons on your car radio.
Ramping - Method of accelerating a motor at increasingly faster step rates in order to reach high feedrates. Ramp rates are measured in full steps/sec/sec. When ramping is used a motor will accelerate and decelerate at the same ramping rate.
