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Rockwell Automation 1785-Lxxx Enhanced and Ethernet PLC-5 Programmable Controllers User Manual

Page 113

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Publication 1785-UM012D-EN-P - July 2005

Communicating with a PLC-5 Adapter Channel 7-15

Example Bidirectional Repeating Block Transfer in
PLC-5/250 Supervisory Controller

Effects of Programming Block-Transfers to an Adapter-Mode
Controller Channel on Discrete Data Transfer

Because the discrete transfer configuration files are used for discrete data
transfer as well as block-transfer status exchanges between a supervisory
controller and adapter-mode controller channel, performing multiple
block-transfer to and from the adapter-mode controller channel impacts
discrete data transfer.

BTR

BLOCK TRANSFER READ

RACK

GROUP

MODULE

CONTROL BLOCK

002

0

0

BR020:0

DATA FILE

BT LENGTH

1BTD1:0

0

PLC-5 adapter-mode processor is configured for rack 2

CONTINUOUS

N

BTW

BLOCK TRANSFER WRITE

RACK

GROUP

MODULE

CONTROL BLOCK

002

0

0

BW020:0

DATA FILE

BT LENGTH

1BTD2:0

0

CONTINUOUS

N

BT TIMEOUT

3

BT TIMEOUT

3

FILE ARITH/LOGICAL

CONTROL

LENGTH

1R0:0

64

BTR Done Bit

Data Not Valid Bit

BR020:0

DN

I:020

10

POSITION

MODE

0

ALL

DEST

EXPRESSION

#1N0:0

1BTD1:0

EN

DN

ER

EN

DN

ER

EN

DN

ER

FAL

BR020:0

EN

BWO20:0

EN

BR020:0

EN

BWO20:0

EN

Enter the following parameters in the
block-transfer instructions in the
supervisory processor.

Set the length to 0.

Use the remote I/O rack number for
which you configure the
adapter-mode processor.

Use the group and module numbers for
which the adapter-mode processor is
configured.

Condition the use of BTR data with a
"data valid" bit.

All address comments for contacts shown in
the following examples represent the set (1)
state of the bit in the PLC-5 processor.

Read data from adapter-mode processor

Send data to adapter-mode processor

Buffer read data from adapter-mode
processor to work area