Specifications

SECTION 13 GLOSSARY

SECTION 13 - GLOSSARY

Absolute Mode

A positioning coordinate reference wherein all positions are specified relative to some reference, or

"home" position. This is different from relative, or incremental programming, where distances are

specified relative to the current position.

Baud Rate

A term used frequently in serial data communications but often is misunderstood. A 'baud' is defined as

the reciprocal of the shortest pulse duration in a data word (signal), including start, stop, and parity bits.

This is often taken to mean the same as "bits per second", a term that expresses only the number of 'data'

bits per second. Very often, the parity bit is included as an information or data bit.

Break Signal

A break is often used to signal a remote computer to stop transmission. Typically a Break Signal is

produced by holding the data terminal equipment (DTE) transmit data (TXD) low for some time

significantly longer than the time it takes to send a word.

Daisychain/ MultiDrop

A term used to describe the linking of several RS422/RS232C devices in a sequence such that a single

data stream flows through one device and on to the next. Daisy-chained devices usually are distinguished

by device addresses, which serve to indicate the desired destination for data in the stream.

Debug

A term used to define refinements to a system or program that remove undesirable effects.

EEPROM

Electrically Erasable Programmable Read-Only Memory. A memory device frequently used with

microprocessors, that can be erased and reprogrammed with- out removing it from the circuit. This

creates non-volatile memory; i.e. memory that won't be lost if the power is turned off.

Hard Limit Switch

A switch (i.e. photo, Hall-effect or mechanical) that defines the absolute limit of motion in a particular

direction. It may be used to prevent collisions or out-of-bounds conditions.

Home

A reference position in a motion control system, usually derived from a mechanical datum. Often

designated as the "zero" position.

Home Limit Switch

The switch used to establish the reference position designated "home".

Program Counter

The Program Counter is used by the processor to point to the address of the next instruction to be

executed by the processor in the stored program mode.

Mask

A binary-weighted number that conceals some or all of the bits in an associated memory address or

Relative Mode

A coordinate system where positions or distances are specified relative to the current position.

Stack