Queue Capacity - Allen-Bradley A-B QUALITY DL20 Series User Manual

Dataliner message display

Table of Contents

Chapter 5

Run Mode

Queue Capacity

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.

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.

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.

Boiler pressure is

Boiler pressure is 775

Table of Contents

Table of Contents