Rockwell-automation Logix5000 Controllers Produced and Consumed Tags P Uživatelský manuál stáhnout pdf (Strana 32)

Chapter 2 Produce a Large Array

In addition, the array must contain an extra 122 elements. In other words, it must

be 122 elements greater than the greatest number of elements that you want to

transfer.

• These elements serve as a buffer.

• Because each packet contains the same number of elements, the buffer

prevents the controller from copying beyond the boundaries of the array.

• Without the buffer, this would occur if the last packet contained fewer than

123 elements of actual data.

Follow these steps to produce a large array.

1. In the Controller Tags folder of the controller project that produces the

array, create these tags.

P Tag Name Type

array_ack DINT[2]

array_packet DINT[125]

2. Convert array_ack to a consumed tag.

For Specify

Controller Name of the controller that is receiving the packet.

Remote Tag Name array_ack

Both controllers use the same name for this data.

3. In either the Controller Tags folder or the tags folder of the program that

will contain the logic for the transfer, create these tags.

Tag Name Type

array DINT[x] where x equals the number of elements to transfer plus

122 elements

array_offset DINT

array_size DINT

array_transfer_time DINT

array_transfer_time_max DINT

array_transfer_timer TIMER

4. In the array_size tag, enter the number of elements of real data.

The value of x from step 3 minus the 122 elements of buffer.

5. Create or open a routine for the logic that creates packets of data.

Produce a large array

32 Rockwell Automation Publication 1756-PM011F-EN-P - October 2014

1 2 ... 27 28 29 30 31 32 33 34 35 36 37 38 39 40

Žádné komentáře

Rockwell-automation Logix5000 Controllers Produced and Consumed Tags P Uživatelský manuál Strana 32