Rockwell Automation 6008-SV2R VMEbus remote I/O Scanner - Manual (Page 8)

Preface
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This table defines common terms:
This term: Refers to the:
scanner both remote scanners (catalog numbers 6008ĆSV1R and 6008ĆSV2R)
VME master processor main CPU of your VME system
The VME master processor runs the application program that
accesses the scanner. A VME system can have more than one VME
master processor, each assigned different duties and both accessing
the same scanner(s).
VME chassis frame that VME cards are mounted in
Both the scanner and the VME master processor are mounted in the
chassis along with other VME hardware.
VMEbus circuit board or backplane mounted in the chassis that the scanner, the
VME master processor, and other VME cards plug into
I/O chassis AllenĆBradley 1771 series I/O chassis
This is the frame that houses the I/O modules, power supply, and
adapter or PLC processor.
input image table area of global memory in the scanner that contains the data from the
input terminals of input modules
When an input switch is closed its corresponding input bit in the image
table is set to 1.
output image table area of global memory in the scanner that contains output data for
terminals of output modules
When a bit is set to 1, the corresponding output turns on.
block transfer transfer of data between an intelligent I/O module and a scanner
A block transfer sends as many as 64 words of data at a time.
general data area designated area of global VME memory, existing within the scanner,
that is used to pass information between the scanner and a VME
master processor.
Scanner commands are processed in this data area.
global RAM an area of global VME memory in the scanner that can be accessed
by both the scanner and the VME master processor(s).
This area of memory is the key means for communication between the
scanner and the VME master
semaphore bit bit that indicates whether part of the global RAM (the general data
area) is being used.
Typically this bit is used to prevent multiple masters or the scanner
from writing to the general data area simultaneously.
scan list list that the scanner maintains internally to determine the I/O racks that
it is to scan, and the order in which it is to scan them.
You create the scan list using the AUTOCONFIGURE command or the
SCAN LIST command.
Terms