Queue capacity – Rockwell Automation 2706 DL20 SERIES G USER MANUAL User Manual

Page 52

Chapter 5
Run Mode

5–4

Unloading Queues

A queued message is displayed immediately if there are no messages in the
queue, or as soon as any previously-queued messages have been completely
executed. The message may also be shown on slave displays, or it may be
listed on a printer. The message is evaluated up to the first control V.

Boiler pressure is

At this point, the variable queue still looks like this:

First entry:

775

Second entry:

451

Now, the first entry is taken from the queue.

Boiler pressure is 775

The queue now looks like this:

First entry:

451

The message is then evaluated at the second variable.

Boiler pressure is 775 PSI, temperature is

Now, the second variable is unqueued, leaving both queues empty, and the
message is displayed.

Boiler pressure is 775 PSI; temperature is 451 degrees.

Both the data queue and the message queue have a capacity of twenty entries.
The DL20 will ignore all entries when the queue is full. Because of this, the
DL20 is limited to twenty variables embedded within any one stored
message.

Queue Capacity