Rockwell Automation 1395 Node Adapter Board - Manual (Page 24)

Chapter 3
Functional Description
3-12
Data Storage
In order to use the block transfer blocks in the PLC Controller program, it
is necessary to reserve several words for data storage. Some of these words
are required for internal use by the block transfer function and some
contain the block transfer message information. In the PLC 5
TM , the BTW
and BTR blocks require the use of two sets of words. Figure 3.7 illustrates
the BTW and BTR blocks used for block transfer in the PLC 5
TM along
with example information associated with these blocks. A brief description
of the information contained in these blocks specifically for the PLC 5
TM
follows. For more detailed information on the PLC 5 TM and the PLC 3 TM
refer to the appropriate PLC Controller documentation.
Figure 3.7
PLC Controller Block Transfer Blocks
BTW
Block Transfer Write
Rack:
Group:
Module:
Control Blk.:
Data File:
Length:
Continuous:
1
0
0
#N111:5
6
N
#N111:0
(EN)
(DN)
(ER)
BTR
Block Transfer Read
Rack:
Group:
Module:
Control Blk.:
Data File:
Length:
Continuous:
1
0
0
#N111:50
40
N
#N111:90
(EN)
(DN)
(ER)
Rack – the rack number as set by the switch settings on the Node Adapter
Board.
Group – the group number of the first group in the rack associated with the
Node Adapter Board. In Figure 3.5, the rack has been setup as a full 8
group rack, therefore, the first group is 0. If half rack is selected the first
group in the rack is 0 or 4.
Module – the module number associated with the block transfer in the
associated slot. In all cases this will be 0.
Control Block – is a predefined set of words which contain bit information
associated with the PLC Controller block transfer function. In the PLC 5,
the control block requires 5 continuous words. In Figure 3.7, words N111:0
through N111:4 have been reserved for the bit array in the BTW block and
words N111:90 through N111:94 have been reserved for the BTR block.