Installation guide

302 Glossary
NESTING - The ability of an active subroutine to call
another subroutine. The Motion Controller can nest up
to 16 levels.
NONVOLATILE MEMORY - Data storage device that
retains its contents even if power is removed. Examples
are EEPROM, flash memory, and battery-backed RAM.
OPTO-ISOLATION - The electrical separation of the
logic section from the input/output section to achieve
signal separation and to limit electrical noise. The two
systems are coupled together via a transmission of light
energy from a sender (LED) to a receiver (phototransis-
tor).
PARITY -- An error checking scheme used in serial
communications (via the RS-232 or RS-485 port) to
ensure that the data is received by a Motion Controller is
the same as the data sent by a host computer or terminal.
REDUCE CURRENT - Reduction of motor current
during standstill to alleviate motor heating.
RESOLUTION - The minimum position command that
can be executed. Specified in steps per revolution or
some equivalent.
RINGOUT - The transient oscillatory response (prior to
settling down) of a step motor about its final position.
Note: a small wait or dwell time between moves can
alleviate ringout problems.
RS232-C - EIA (Electronic Industries Association)
communication standard to interface devices employing
serial data interchanges. Single-wire connections for
transmit and receive, etc.
RS-485 - EIA (Electronic Industries Association)
communication standard to interface devices employing
serial data interchanges. Two-wire connections (differ-
ential circuits) for transmit and receive, etc. Better than
RS-232 for long wire runs and multi-drop circuits with
many devices.
SINKING - An input that responds to, or output that
produces, a "low" level (signal common or low side of
the input/output power supply) when active.
SOURCING - An input that responds to, or output that
produces, a "high" level (the voltage used for the in-
put/output power supply) when active.
SUBROUTINE - A sequence of lines that may be ac-
cessed from anywhere in a program to preclude having
to program those lines repetitively. This allows shorter,
more powerful, and more efficient programs. See also
NESTING.
TORQUE - Product of the magnitude of a force and its
force arm (radius) to produce rotational movement.
Units of measure are pound-inches, ounce-inches, new-
ton-meters, etc.
TRANSLATOR - A motion control device (also called
"translator drive") that converts input pulses to motor
phase currents to produce motion.
WAIT - A programmed delay or dwell in program
execution (specified in seconds).
XON / XOFF - A computer software "handshaking"
scheme used by a Motion Controller. The Motion Con-
troller sends an XOFF character (ASCII Code 19) when
it receives a command string with a Carriage Return and
has less than 82 characters remaining in its host serial
port buffer. The Controller sends an Xon when available
buffer space reaches 100 characters or in response to an
ID attention with adequate buffer space remaining.
Since it is impossible for the host device to immediately
cease transmissions, the next three characters (subject
to the total serial buffer capacity of forty characters)
received subsequent to the Motion Controller sending the
XOFF character will be stored in the Motion Controller's
serial buffer (a memory dedicated to store characters
that are in the process of transmission).
Similarly, the Motion Controller will not transmit data if
the host device has sent an XOFF character to the
Controller; Motion Controller transmissions will resume
when the Controller receives an XON character.