Rockwell Automation 1747-BSN Backup Scanner Module - Manual (Page 105)

Publication 1747-UM010B-EN-P - September 2003
Module Control and Status Word 6-9
Data Transfer Handshake Word
The following ladder program example shows how to monitor the
status bits in the System Status Word (SSW) and in the Module Status
Word (MSW) that indicate which processor is in the primary mode and
which is in the secondary mode. This information is needed in order
to determine whether the local processor needs to execute the
primary system or the secondary system HSSL data transfer ladder
logic.
File 2 monitors the appropriate SSW and MSW bits and executes
subroutine 4 if the local system is in primary mode.
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
14
0
15 13 12 11 10 9 8 7 6 5 4 3 2 1 0
Block # 1
Block # 2
Block # 3
Block # 4
Block # 5
Block # 6
Block # 7
Block # 8
Block # 9
Block # 10
Block # 11
Block # 12
Block # 13
Block # 14
Block # 15
Block # 16
DTHW (M0:s.3411)
TIP
Set the M1 and M0 file lengths for the 1747-BSN to
the maximum (5548). There is no memory or speed
penalty for creating the maximum buffer size for
these files in the 1747-BSN modules.