Rockwell Automation 1336T Function Block Prog. Manual, Series A/B - Manual (Page 159)

5–43 Block Transfer Services
1336 FORCE — 5.9 August 1995
The Read Node Link operation reads the drive parameter or the node
numbers of the source that is linked to the specified function block
node.
PLC Block Transfer Instruction Data
BTW Instruction Length: 3 Words
BTR Instruction Length: 4 Words
Header
Word 1
PLC Hex Value
0F04
Message Structure
Header
Word 2
Header
Word 3
PLC Request –– Block Transfer Write
Header Word 1
Header Word 2
Header Word 3
0
0
PLC Hex Value
0F04 –– Message OK
8F04 –– Message Error
ID N
8NID
High Byte Low Byte
Linked Source
Data
Word 4
Drive Response –– Block Transfer Read
where:
N = the node number
ID = the block ID number
ID N
8NID
High Byte Low Byte
If N=16, 8NID becomes 90ID.
Message Operation
The Read Node Link operation reads the output parameter that is
linked to the function block node specified in word 3.
❒ N, specified in the high byte, indicates the node number.
❒
ID, specified in the low byte, indicates the block ID number.
The data returned from the drive identifies the source parameter. If
the node is linked to a drive parameter, word 4 contains the
parameter number. If the node is linked to another function block
node, word 4 contains the node number and block ID number.
Chapter 2 contains additional information that is helpful for
understanding node reference numbers.
Node Adjustment:
Read Node Link