Rockwell Automation 2706-MB1 MESSAGEVIEW 421 SOFTWARE MANUAL - Manual (Page 317)

Glossary G–9
Publication 2706-817
R –
Real Time Clock – The MessageView terminal has its own
battery-operated clock, also referred to as RTC. It provides values for
time or date variables in displayed messages. The terminal’s clock
may be set using the RTC Download command from
MessageBuilder software, or the terminal operator may set it.
RS-232 – A serial link for transmitting data to and from the RS-232
port of a MessageView terminal. Communication with a personal
computer requires a DF1 connection, whose parameters are set up in
the terminal’s Firmware. Communication with any other device
requires that the RS-232 port Parameters are set up in the
Application. Communication with a Slave Device requires a
RS-232/Simplex connection.
Remote I/O – A serial link for transmitting data to and from a PLC
or SLC processor/scanner and the Remote I/O port of a
MessageView terminal. Also supports Block Transfer of data that is
moved using block transfer ladder instructions.
S –
Save – The process of transferring data stored in RAM memory to a
disk file.
Scaling – Mathematically manipulating data so it may be stored in
one form in a Controller and displayed in another form in the
MessageView terminal.
Select – Select an action to activate a chosen (highlighted) item. In
some cases a mouse click can Choose and select an item in one step.
Slave Device – A device that receives and displays messages from a
Master Device, but does not initiate communication. Slave Devices
include the MessageView 421D Slave Device terminal (Catalog
2706-M1D) and several of the Allen-Bradley Dataliner family.
Slaving – A system in which a Master Device controls one or more
Slave Devices remotely. A MessageView terminal with a
daughterboard and firmware that supports Slave Port can act as a
master device for up to 127 Slave Devices.
SLC – Allen-Bradley trademarked name for Small Logic
Controller.
Special Messages – Messages that affect the MessageView
terminal. They are not displayed or sent to the HE Stack, but may be
triggered as part of the application.