Rockwell Automation 2706 DL40 HARDWARE USER MANUAL - Manual (Page 19)

Chapter 2
Introduction to the DL40
2 – 6
Historical Events Stack
With the DL40’s Historical Events Stack you can record the occurrence and
sequence of some or all of the messages or variable data values that have
been triggered and/or displayed. The 16K bytes of memory available for this
record will hold about 1,000 events. You can view this record on the DL40
itself, or obtain a printout for offline reference.
Clock Operations
The DL40 contains a real-time battery-backed clock that will keep accurate
time even when power is removed from the unit. The DL40 can display the
current time and/or date in either AM/PM or 24-hour military format.
Date and time information can be displayed as part of any triggered message,
and passed on to a PLC. You can also date- or time-stamp events as they are
recorded in the Historical Events Stack.
You can set the DL40 internal clock from the front panel menus, from a PLC,
or through the Offline Programming Software.
RS-232 and RS-485 Ports
The DL40 has both an RS-232 and RS-485 port.
The RS-232 port can be used to:
•
upload or download message files from a computer
•
print messages and/or Historical Event Stack contents
•
upload or download message files using a data (tape) recorder
The RS-485 port can be used to:
•
trigger messages with or without variable data content
•
multi-drop upload or download message files from a personal computer
•
send messages to slave message displays
•
input ASCII data via keyboard or wedge
Debug Mode (Parallel Port Version)
The DL40 allows you to display the binary status (1 or 0 value) of both the
strobe and data lines to check the output of a programmable controller.