Rockwell Automation 1336T Function Block Prog. Manual, Series A/B User Manual

Page 44

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2–10

System Component Detail

1336 FORCE — 5.9 August 1995

DriveBlockEditor Node References

If you are using DriveTools, you can reference a specific node of a
particular function block by specifying the block ID:node number.
For example, to reference block number 6, node 2, you would enter
6:2.

Even though the DriveTools’ DriveBlockEditor allows you to
reference I/O nodes as block ID:node number, the DriveBlockEditor
software converts the decimal information into the single word
reference number. DriveTools uses emulated block transfer services
because it uses the Data Highway Plus protocol. Block transfer
services are covered in Chapter 5.

Understanding PLC and Drive Node References

Node references are easier to understand when you use hexadecimal
values. The drive and PLC block transfers both reference the node
number and block ID as a single word in the following form:

15 14 13

8

7

0

0

Node #

Block ID

MSB

1

LSB

MSB = Most Significant Bit
LSB = Least Significant Bit

Bit

Description

15

0 –

The value or link reference represents a standard linear Motor Control
board or a PLC Communication board file parameter number.

1 –

The value or link reference represents a function block I/O node
reference.

14

0

8–13

Contains the I/O node reference.

0–7

Contains the block ID number.

The upper-most four bits, bits 12 – 15, typically have a value of 8

Hex

for most function block node references. The value will not exceed
8

Hex

unless you reference a node number of 16 or greater.

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