Allen-Bradley A-B QUALITY DL20 Series User Manual page 153

Overview
PLC-2
Programming Examples
Application Notes
This appendix provides examples of interfacing a DL20 with PLC-2 and
PLC-5 Programmable Controllers through the DL20 parallel port.
Programming examples and connection diagrams show how to transfer
message triggers and variable data from 1771 I/O modules to the DL20
parallel port.
The examples and diagrams used in this appendix are included solely for
illustrative purposes.
ATTENTION: The DL20 has single direction communication
and should be used only for non-critical display applications.
!
Single direction communication does not provide verification that
messages from the programmable controller have been received
and displayed by the DL20.
The PLC-2 processor configuration for both examples is listed below. This
configuration may vary for different applications.
1. A 1770-T3 Industrial Terminal is used.
2. The "SEARCH 50" command configures the data table for 1 data table
block and 2 I/O racks. The Mini PLC-2/15 or Mini PLC-2/05 processors
automatically default to the 2 I/O rack configuration.
3. The output modules (2) are in Rack 1, module group 0 (word address
010).
4. The DL20 configuration is defined separately for each program example.
high true logic
BCD messages / variable data
time driven
DC inputs
scan = 4, debounce = 1
Appendix
G
A–B
G–1