Rockwell Automation 2706-MB1 MESSAGEVIEW 421 SOFTWARE MANUAL - Manual (Page 108)

5–19 Communications Overview
Publication 2706-817
Each block transfer must have certain information specified:
•
Enabled: whether the block transfer enabled or disabled.
•
Address: the starting address to read or write the block transfer.
•
Mode: select R for a Read operation or W for a Write operation.
•
Length: how many words are transferred (1 to 64). The
MessageView terminal uses the length to identify data blocks.
Each block transfer read must be a unique length and each block
transfer write must be a unique length. However a read block can
be the same length as a write block.
A length of 63 is reserved for Pass-Through.
•
Pass-Through: (This option is not available at this time.)
•
Block Transfer Timeout: specifies a timeout value for
transferring applications using Pass-Through. A value of 0
disables the timeout.
•
Each block transfer requires a corresponding Block Transfer
Write or Block Transfer Read instruction in the ladder program
for the controller. The Data File and Length settings must match
the Data File and Length settings in the Block Transfer dialog.
BTR or BTW
BLOCK TRANSFER READ/WRITE
Rack 03
Group 0
Module 0
Control Block N36:0
Data File N37:1
Length 4
Continuous N
High or Low Byte (Always 0 for MessageView)
MessageView Rack Assignment
Group No. 0
! 7
Address of the data file which is written or read.
Must match the address entered in the Block
Transfer dialog.
Length of the data being transferred. Must match
the length entered in the Block Transfer dialog.
File that controls how the instruction works
Operating mode of the transfer