Rockwell Automation 2706-MB1 MESSAGEVIEW 421 SOFTWARE MANUAL - Manual (Page 65)

4–17 Planning an Application
Publication 2706-817
Slave Packet
A message intended for transmission to a slave device has the
following format:
[Optional Control Byte][ASCII Text][Optional Display
Mode Byte][Slave Address Byte][Line Number Byte][CR]
MessageBuilder software allows for the automatic or manual
insertion of the Optional Control Byte and Optional Display Mode
Byte.
If you choose to embed them manually, the individual control codes
are found on Page 7–42. The slave packet fields are:
•
Control Byte: specifies text size or clears the slave display.
•
ASCII Text: the message itself, including embedded variables and
graphics. The maximum length for any message is 100
characters; in a slave packet the control codes are not counted.
•
Display Mode Byte: specifies scrolling, centering and hold
message options.
•
Slave Address Byte: specifies the Slave Device node address, an
integer from 1 to 127. Addresses 1-126 specify an individual
node where a Slave Device is connected. Address 127 addresses
all Slave Devices.
•
Line Number Byte: specifies a Display Line number. An integer
from 1 to 4 specifies a specific line; 50 clears all lines if Control
Byte was Ctrl-C.
•
CR: a carriage return, to signal the end of the message.
Note: Non–printable codes and characters are not included in the
character count for slaved messages.
Slave device alarm relay
The MessageView terminal supports a slave device alarm relay. A
message with the Relay attribute enabled will energize the slave
device alarm relay when the slave device receives the relay packet.
The alarm will remain energized until a message with the Relay
attribute disabled is slaved to that node and line number, replacing
the alarm message and de-energizing the alarm.
The following slave device supports an alarm relay:
•
DL50