Ormec SMLC 30 Installation & Operation Manual page 56

ServoWire Motion & Logic Controller Manual
Factory network adapters ‐ A physical layer network interface which plugs into the SMLC and contains a
co‐processor for performing factory network communications (e.g. PROFIBUS requires a factory network
adapter card).
Follower ‐ A servo axis, which is controlling its motion as a function of MotionDATA, generated by a
pacer axis. Follower motions are generated with the MC_GEAR statement in the SMLC.
Home Position ‐ A reference position for either a servo or an encoder axis.
Hardware Travel Limits HTL's ‐ Inputs to ServoWire drive which must be asserted (sinking current), or
disabled by software setting, for a servo axis to operate.
IEC‐61131‐3 ‐ A global standard defining programming languages for industrial control.
Loop Update ‐ Servo Loops in the SMLC systems are updated by the Motherboard at rates of between
500 and 2,000 times per second. At each Loop Update, (Loop Rate) the SMLC performs housekeeping
operations such as updating the axis position and the output signals in addition to performing the real‐
time control algorithm for that servomotor.
Machine Sensor ‐ Any of a number of types of ON‐OFF sensors, like proximity switches or mechanical
switches mounted to a machine.
MODBUS – MODBUS® Protocol is a messaging structure developed by Modicon in 1979, used to
establish master‐slave/client‐server communication between intelligent devices. It is a de facto
standard, truly open and the most widely used network protocol in the industrial manufacturing
environment.
MODBUS/TCP – Modbus/TCP is an implementation of the MODBUS Protocol, allowing MODBUS
messages to be transferred via Ethernet.
OPC – OLE for Process Control. A set of open standards for connectivity and interoperability of industrial
automation and enterprise systems.
Pacer ‐ A servo or encoder axis which transmits either its actual or commanded motion to other servo
axes through the MotionDATA communication channel to another servo axis.
Pacer Encoder ‐ An incremental encoder or device that generates quadrature signals which are used by
other servo axes when they operate as followers.
Quadrature ‐ Quadrature or "phase quadrature" signals are the most commonly used method of
electronically determining or transmitting bi‐directional position information. The two‐quadrature
signals are digital square waves, which have their cycles displaced 90 degrees (of the 360 electrical
degrees in the repeated waveform). All four edges of the two digital signals are normally used for the
maximum possible position resolution ("4x").
RTOS ‐ Real‐Time Operating System.
Registration Control ‐ The act of maintaining a fixed position relationship between machine tooling and
a product in the machine. Registration is normally measured by capturing the tooling position with
respect to the product using a registration sensor of some type. It is controlled by phasing the tooling
ahead or behind based on the difference between the actual and desired positional orientation.
Resolver ‐ A position transducer used to determine the position of a motor. Resolvers are rotary
transformer devices with analog interfaces. However, in ORMEC Motion Control systems which use
resolvers, the servo drive decodes the resolver position digitally.
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Terms & Mnemonics
SMLC‐004a