Allen-Bradley A-B QUALITY DL20 Series User Manual page 70

Addressable Master
The addressable master option allows you to uniquely address over 100
DL20s linked to the same host.
A message trigger is only recognized by the similarly addressed master
display. To set up a master address, use the special function Set Up Master.
A master address can be any number from 1 to 127 with some exceptions.
The address assigned in the sequence is the decimal value of the associated
ASCII symbol.
To trigger a display with an address of 65, the character "A" is typed.
Certain addresses are not valid for DL20s. These illegal addresses are
decimal 0, 4, 6, 13, 18, 20, 22, 43, 45, 48-57. Setting a master address of 0
disables the feature. More than one master may have the same address
assigned to it. Invalid addresses may result in the display of invalid data.
Note: A message trigger or variable data entry with an address of 127 is
recognized by all DL20s regardless of their address. This provides a quick
and easy method of triggering a message on all interconnected masters.
The format of the message trigger is:
MESSAGE
CONTROL T
The format of a variable is:
VARIABLE
CONTROL V
DL20 master addresses are always one byte (1 - 127 Decimal or 1 - 7F Hex).
Set the DL20 address according to the decimal equivalent (1-127). Use
Appendix A to convert ASCII characters, hex, and decimal values.
Chapter 6
The Serial Port
MASTER
NUMBER ADDRESS
MASTER
DATA ADDRESS
CARRIAGE
RETURN
CARRIAGE
RETURN
6–5