Rockwell Automation 1747-BSN Backup Scanner Module - Manual (Page 101)

Publication 1747-UM010B-EN-P - September 2003
Module Control and Status Word 6-5
•
RIO Communication: This bit is set when a problem occurs
with the RIO link in the local (bit 4) or remote (bit 12) 1747-BSN
module. The type of problem that may occur is different for
primary and secondary systems (as shown below). The normal
state of this bit is OFF):
1. Primary mode: The channel is faulted or has communication
errors.
2. Secondary: No communication could be seen by this module
in the RIO link. This indicates that the primary RIO link is not
working or that a problem exists in the RIO connection to the
secondary 1747-BSN module.
•
Processor Fault: This bit is set when one of the processors
(SLC 5/0x), either the local (bit 5) or remote (bit 13), is in failure
or is in Program or Test mode. The normal state of this bit is
OFF.
•
Primary/Secondary System: This bit is set when the local
(bit 6) or remote (bit 14) system is in the primary mode,
otherwise the system is in the secondary mode. Bits 6 and 14 are
never set at the same time. During power-up or switchover time,
these bits can be clear at the same time. The normal operation is
with one bit set for the primary system and one bit clear for the
secondary system.
Transferring Data over the
High-Speed Serial Link
(HSSL) Two M0 file words and one M1 file word are used to control the
transfer of data from the primary SLC processor to the secondary SLC
processor. This link should be used to transfer internal processor data
that must be kept current in the secondary processor in the event that
a switchover takes place, making the secondary processor the primary
processor. Actual input data from remote I/O chassis need not be
transferred over this link since the secondary 1747-BSN allows the
secondary processor to receive this data from the remote I/O network
in a “listen mode”. Outputs are only controlled by the primary
processor.
The three words used to accomplish data transfer over the HSSL are:
1. M0:s.3410: Data Transfer Control Word (DTCW)
This word is used by the primary processor to initiate the
transfer of data to the primary 1747-BSN. This data is ultimately
transferred to the secondary 1747-BSN over the HSSL, then to
the secondary processor.