Allen-Bradley controllogix 1756-L63, User Manual

Page: 326 / 435

Publication 1756-UM001E-EN-P - August 2002
20-10 Communicate Over a Remote I/O Network
Read or Write Data To or
From a Block Transfer
Module
Use this procedure to transfer data to or from a module that requires
block transfers.
1. The MSG instruction reads 16-bit integers (INTs) from the BT
module and stores them in a temporary array of INTs.
2. An FAL instruction converts the INTs to 32-bit integers (DINTs).
Logix5000 controllers execute more efficiently and use less
memory when working with DINTs.
1. An FAL instruction converts the 32-bit integers (DINTs) from the
Logix5000 controller to 16-bit integers (INTs):
•
Logix5000 controllers execute more efficiently and use less
memory when working with DINTs.
•
The instruction stores the data in a temporary array of INTs.
2. The MSG instruction writes the INTs from the temporary array to
BT module.
Block Transfer Read Data from a
BT module Buffer of INTs DINTs for use in
the project
Word 1
int_buffer_read[0] dints_input[0]
Word 2
int_buffer_read[1] dints_input[1]
Word 3
int_buffer_read[2] dints_input[2]
1
2
Block Transfer Write DINTs from the
project Buffer of INTs Data for a BT
module
dints_output[0] int_buffer_write[0]
Word 1
dints_output[1] int_buffer_write[1]
Word 2
dints_output[2] int_buffer_write[2]
Word 3
1
2