Rockwell Automation 2706-M1 MESSAGEVIEW 421 HARDWARE MANUAL - Manual (Page 83)

4–23 Running Applications
Publication 2706–816
Report the HE Stack status with [Ctrl-H]
Used by the terminal to report 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.
Terminal output buffer
The terminal is designed to handle at least 20 outgoing response
messages via an output buffer. If the ASCII Triggering device’s
serial baud rate is set low and an enormous number of data entry
inputs or function key presses occurs, the output buffer will
overflow. While the buffer is in this condition, any new data input
will be lost.
Hardware Handshaking
The terminal monitors the CTS/RTS lines between the terminal and
the ASCII Triggering device if the embedded application has the
Hardware Handshake attribute enabled.
•
If the MessageView terminal input buffer is full, the terminal will
assert its RTS line so the ASCII device stops sending commands.
•
If the MessageView terminal detects an asserted CTS line, it will
stop sending character information. After 30 seconds it displays a
CTS error message for 2 seconds and then clears the display. If
the CTS line is still asserted, after 30 seconds it displays the CTS
error message again for 2 seconds and then clears the display.
This cycle is repeated until the CTS signal is non-asserted.