Rockwell Automation 1772-LS_LSP,D17726.8.6 PROG/OPER MANUAL-MINI PLC-2/05 - Manual (Page 252)

Glossary
Appendix B
BĆ16
PROM
Programmable Read Only memory. A type of ROM that requires an electrical
operation to store data. In use, bits, or words are read on demand but
not changed.
Rack
An I/O addressing unit that corresponds to 8 input image table words and 8
output image table words.
Rack Fault
1) A red diagnostic indicator that lights to signal a loss of communication
between the processor and any remote I/O chassis. 2) The condition which is
based on the loss of communication.
RAM
Random Access Memory. The type of memory in which data access is
independent of the data most recently accessed.
Red
1) To acquire data from a storage device. 2) The transfer of data between
devices such as a peripheral device and a computer.
Read/Write Memory
A memory where data can be stored (write mode) or accessed (read mode). The
write mode replaces previously stored data with current data; the read mode
does not alter stored data.
Record
1) A group of data that is stored together and/or used together in processing.
2) A collection of related data treated as a unit. See File.
Register
A memory word or area used for temporary storage of data used with
mathematical, logical, or transferal functions.
Relay Logic
A representation of the program or other logic in a form normally used
for relays.
Remote I/O processor
A processor system where some of all of the I/O racks are remotely mounted
from the processor. The location of remote I/O racks from the processor may
vary depending on the application and the processor used. Also see Local
I/O Processor.
Remote Mode Selection
A feature which allows the user to select or change processor modes of
operation with a peripheral device from a remote location.