Rockwell Automation 57C570 AutoMax PC3000 User Manual - Manual (Page 283)

HĆ3
handshake: a series of signals between a computer (DTE) and a peripheral
device (DCE; e.g., a modem) that establishes the parameters required for
passing data.
heatĆshrinkable: describes tubes, caps, sleeves, boots, or other forms of
plastic which shrink when heated to encapsulate, protect or insulate
connections, splices, terminations and other configurations.
impedance: the total opposition a circuit, cable or component offers to
alternating current. It includes both resistance and reactance and is generally
expressed in ohms.
input image table: See I/O image table.
I/O chassis: a chassis (housing) for the I/O modules and either a processor to
control the I/O module or an adapter to interface a scanner to the I/O modules.
I/O group: a group of input and/or output circuits that corresponds to a word
(16 bits) each in the input and output image tables.
I/O image table: an area in memory (scanner or adapter module) with
addresses corresponding to each input and output module.
I/O rack: an I/O addressing unit that corresponds to 8 input image table words
and 8 output image table words. A rack can contain a maximum of 8 I/O groups
for a maximum of 128 I/O with unique addressing of I/O modules.
impedance match: a condition whereby an impedance of a particular circuit,
cable or component is the same as the impedance of the circuit, cable or device
to which it is connected.
ISA bus: the backplane in the personal computer (PC); it enables the cards in
the PC to talk to the computer's microprocessor or to each other.
jack: a connecting device into which a plug can be inserted to make circuit
connections.
jacket: the outer sheath which protects against the environment and may also
provide additional insulation.
master: a device (programmable controller with I/O modules or a workstation)
that sends data to and collects data from devices connected on a network.
maximum recommended pulling tension: the maximum load which can be
applied along the axis of a cable without breaking the fibers.
microbend loss: attenuation caused by excessive cable bending or
manufacturing flaws.
micron: one millionth of a meter or 0.000039 inch.
minimum bend radius: the smallest radius to which a cable can be bent
without damaging the fiber.
mismatch: a condition whereby an impedance of a particular circuit, cable or
component is not equal to the impedance of the circuit, cable or device to which
it is connected.
modem: a device that modulates digital information from a programmable
controller or computer to an analog signal that is transported over phone lines,
radio waves, or satellite transmissions and demodulates the analog back into
digital data at the receiving sites.
module slot: a location for installing a module. In typical modular construction,
modules plug into a backplane; each module slides into a slot that lines it up
with its backplane connector.
NET: PC3000 Network Interface. Stores and manipulates status and data
registers for the PC3000 DCSĆNET network drop. See also DCSĆNET network.
node: devices that are connected to the AutoMax DCSĆNET network. See also
Drop.