INTRODUCTION
GLOSSARY OF TERMS AND ABBREVIATIONS (continued)
1 - 4
I-E96-215A
®
GLOSSARY OF TERMS AND ABBREVIATIONS
(continued)
®
INFI-NET and Network 90 are registered trademarks of the Elsag Bailey Process Automation.
Table 1-3. Glossary of Terms and Abbreviations (continued)
Term
Definition
Function Block
The occurrence of a function code at a block address of a module.
Function Code
An algorithm which defines specific functions. These functions are linked together to
form the control strategy.
INFI-NET
®
Advanced data communication highway.
LED
Light Emitting Diode.
LSB
Least Significant Bit. The bit of a binary number that carries the least numerical
weight.
MFT
Machine Fault Timer. Reset by the processor during normal operation. If not reset
regularly, the MFT times out and the module stops.
MMU
Module Mounting Unit. A card cage that provides electrical and communication sup-
port for INFI 90/Network 90
®
modules.
Module Bus
A serial communication link between a process control module and other process
control modules.
MSB
Most Significant Bit. The bit of a binary number that carries the most numerical
weight.
Node
A point of interconnection to a network.
Nonfatal Error
Any failure or error that does not prevent the module from executing the
configuration.
NVRAM
Nonvolatile random access memory. Retains stored information when power is
removed.
OIS
Operator Interface Station. Integrated operator console with data acquisition and
reporting capabilities. It provides a digital access into the process for flexible control
and monitoring.
PCU
Process Control Unit. A node on the plant-wide communication network that contains
control and slave modules.
Plant Loop
Network 90 data communication highway.
RAM
Random Access Memory. Contents are lost when power removed.
ROM
Read Only Memory. Contents remain when power removed.
TM
Termination Module. Provides input/output connection between plant equipment and
the INFI 90/Network 90 modules.
TU
Termination Unit. Provides input/output connection between plant equipment and the
INFI 90/Network 90 modules.