Rockwell Automation 1395 Multi-Comm Hardware/Software - Manual (Page 37)

Chapter 3
Configuration & Interfacing
3–26
Block Transfer Write in Process – Is set when a block transfer write to
the Drive is in process. This bit remains set until the message has been
received and placed in the Drive’s internal message buffer.
IMPORTANT: Do not attempt to initiate another block transfer request
while this bit is set. The Drive will not respond to the request.
Block Transfer Read Data Available – Is set when the Drive has data
available for the PLC to read.
Block Transfer Wait (Message being processed) – Indicates that the
Drive has received a block transfer request and is processing the request.
This bit is set at the completion of the Block Transfer Write and is cleared
at the reception of the response (start of the Block Transfer Read request).
Block Transfer Request Error – When set, indicates that the Drive has
received an incorrect block transfer request from the PLC Controller. This
bit is cleared when a valid block transfer request is made.
Data Storage
Channel in Control – Indicates which channel has control of the Drive.
If bit = 0 then channel A has control, if bit = 1 then Channel B has control.
In order to use block transfer instructions 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

Controllers,
the BTW and BTR instructions require the use of two sets of words. Figure
3–18 illustrates the BTW and BTR blocks in the PLC–5 along with a brief
description of the information contained in these blocks. For detailed
information on these instructions refer to the PLC–5 Controller instruction
manual.
Figure 3-18. PLC Controller Block Transfer Blocks
BLOCK TRANSFER WRITE
RACK: 1
0
BTW
GROUP:
MODULE:
CONTROL Blk:
DATA FILE:
LENGTH:
CONTINUOUS:
# N111 : 0
0
# N111 : 5
6
N
(EN)
(DN)
(ER)
BLOCK TRANSFER READ
RACK: 1
0
BTR
GROUP:
MODULE:
CONTROL Blk:
DATA FILE:
LENGTH:
CONTINUOUS:
# N111 : 90
0
# N111 : 50
40
N
(EN)
(DN)
(ER)
Rack: – The rack number for the Drive as specified by the switch settings
on the MCA board.