Rockwell Automation 1771-IXHR , D17716.5.80 HIGH RESOL.THERMOCOUPLE - Manual (Page 20)

Module Programming
Chapter 4
4Ć2
Block transfer instructions with the PLC–3 processor use one binary file in a
data table section for module location and other related data. This is the block
transfer control file. The block transfer data file stores data that you want
transferred to the module (when programming a block transfer write) or from
the module (when programming a block transfer read). The address of the block
transfer data files are stored in the block transfer control file.
The industrial terminal prompts you to create a control file when a block
transfer instruction is being programmed. The same block transfer control file
is used for both the read and write instructions for your module. A different
block transfer control file is required for every module.
A sample program segment with block transfer instructions is shown in
Figure 4.1, and described below.
Figure 4.1
PLC-3 Family Sample Program Structure
EN
BTR
BLOCK XFER READ
RACK:
GROUP:
MODULE:
DATA:
XXX
X
X = XXXX
XXXX:XXXX
LENGTH:
CNTL:
X
XXXX:XXXX
EN
BTW
BLOCK XFER WRITE
RACK:
GROUP:
MODULE:
DATA:
XXX
X
X = XXXX
XXXX:XXXX
DN
LENGTH:
CNTL:
X
XXXX:XXXX
Pushbutton
Power-up
Bit
Block Transfer
Read Done Bit
ER
ENABLE
DONE
ERROR
12
15
13
ENABLE
DONE
ERROR
02
05
03
Block Transfer
Write Done Bit
1
2
DN
ER
Program Action
At power–up, the user program examines the BTR done bit in the block transfer
read file, initiates a write block transfer to configure the module, and then does
consecutive read block transfers continuously. The power–up bit can be
examined and used anywhere in the program.
Rungs 1 and 2 - Rungs 1 and 2 are the block transfer read and write
instructions. The BTR enable bit in rung 1, being false, initiates the first
read block transfer. After the first read block transfer, the module
performs a block transfer write and then does continuous block transfer
reads until the pushbutton is used to request another block transfer write.
PLC-3 Program Example