Rockwell Automation 2706-MB1 MESSAGEVIEW 421 SOFTWARE MANUAL - Manual (Page 101)

5–12 Communications Overview
Publication 2706-817
Return message number with [Ctrl-N]
Certain types of messages have their message number returned to the
ASCII Triggering device using [Ctrl-K], [Ctrl-I] or [Ctrl-F]. The
terminal uses the [Ctrl-N] command to report all other types of
messages when they are triggered.
Format: [Ctrl-N]Message#[CR]
•
Message# range: 1 to 9999; limited to the subset used in the
application
Example: [Ctrl-N]637[CR]
•
The terminal reports that message #637 was triggered.
Report the HE Stack status with [Ctrl-H]
Used by the terminal to report to the ASCII Triggering device that
the Historical Event Stack is 85%, 95% or 100% full.
Format: [Ctrl-H]HE Stack Status[CR]
•
HE Stack Status range: 85, 95 or 100
Example: [Ctrl-H]85[CR]
•
The Historical Event Stack is 85% full.
On a remote I/O network, the MessageView 421 terminal appears
like any other Remote I/O rack. Configure the terminal to occupy all
or part of a single rack, up to 128 I/O.
Two types of addresses can be assigned to application variables on a
Remote I/O network:
•
discrete - a single input or output bit address
•
block transfer - a series of contiguous word addresses transferred
as a unit.
Important: Plan the addresses before starting to create the
application for most efficient use of memory.
The direction of data transfer over a remote I/O link is from the point
of view of the logic controller:
•
entry variables are BTR (block transfer read): data from the
terminal to the controller
•
display variables are BTW (block transfer write): data from the
controller to the terminal.
Remote I/O
Communication