Rockwell Automation 2706 DL40 HARDWARE USER MANUAL - Manual (Page 48)

Chapter 6
Other Operating Modes
6 – 2
– an updated variable is received for a variable already on the stack and
more than 2 seconds elapse between receiving the original variable
and the updated variable.
– If less than 2 seconds elapse, the original variable put on the stack will
be overwritten by the updated variable.
•
Messages can be accompanied by time & date stamping.
•
Messages are put on the Historical Events Stack each time they are
triggered.
Note: Bit Trigger Run Mode Only – The Bit Trigger Table is put on the
Stack as soon as it is received by the DL40. Each time a message with the
stack attribute set is displayed or redisplayed, an entry for that message is put
on the stack.
Time and Date Stamping of Messages Put on the Stack
•
Requires the Message Attribute to be set using the Onboard Editor or
Offline Programming Software for each message you wish to stamp.
•
The DL40’s real time clock value is added to message data on the stack
when:
– a message is run
– a message is triggered (if it is never run)
– a message is triggered and if the time between triggering and running
is more than 1 minute
– if an additional stack entry is made because variable data is updated
(see above)
– a message is acknowledged
Resetting the Stack
Each time a new application file is downloaded using a Memory Module –
Read from Module , a Tape Functions – Read from Tape , or an Offline
Programming Software Download to DL40 or Read from Tape , the stack
is reset. All previous stack data is lost.
Triggering Special Message number 909 also resets the stack with a loss of
all previous stack data.
Historical Recall
The Historical Recall Mode is entered from the Run Mode by either a
[CTRL] [S] via the DL40 Keyboard Port or by using [SELECT] and
[ENTER ] push buttons on the front panel of the DL40.