Allen-Bradley ControlNet PLC-5 User Manual page 37

Monitoring and Troubleshooting Your ControlNet PLC-5 Backup System
Word Definition
15-19 reserved
20-24 These words are functionally the same as words 10 through 14. The difference
is that words 20 through 24 display the current internal PLC-5 processor state
of these configuration parameters. When in Run mode, the PLC-5 processor
will continuously update words 20 through 24. In other words, the software
tool will write the configuration parameters into words 10 through 14, while the
PLC-5 processor will write its internal PLC-5 processor state of these
configuration parameters into words 20 through 24. When you accept
configuration changes, the configuration parameters in words 10 through 14
are copied into words 20 through 24.
25 Adjusted Maximum Program Scan Time. This word is the Maximum Program
Scan Time parameter, rounded up to the next integer multiple of the NUT value.
This word is written by the PLC-5 processor, and is continuously updated while
the processor is in Run mode.
26 The number of NUTs per Maximum Program Scan Time. This word is the
number of NUTs in the Adjusted Maximum Program Scan Time. This word is
written by the PLC-5 processor, and is continuously updated while the
processor is in Run mode.
27 The NUT time, in 10 microsecond units, is continuously written here while the
processor is in Run mode.
28 Configuration status. This word gives either the reason why the configuration
attempt was unsuccessful, or whether the configuration parameters were
overwritten because the system went into Run mode as a secondary system.
• 6 - Operation mode word invalid
• 7 - Equivalence Check word invalid
• 8 - Designated Primary word invalid
• 9 - Max Program Scan Time word invalid
• 10 - Configuration parameters were overwritten by the primary system
• 12 - Crossload parameter invalid
29 reserved
30 Accept Configuration Changes. A non-zero value written into this location
forces the primary PLC-5 processor to accept the new configuration
parameters. After the PLC-5 processor has done so, it will zero this word. This
command is only in effect for the primary processor. The configuration
parameters you change are:
• Operational mode
• Maximum Program scan time
• Equivalence checks
• Designated primary
• Crossload parameters
31 Force Switchover. A non-zero value written into this location forces the primary
processor to switch over control to a secondary processor. After the processor
has read the non-zero value, the PLC-5 processor will zero this word. This
command works for both the primary and secondary processors. However, if
there is a Designated Primary, this command will not function.
32 Clear Diagnostic Counters. A non-zero value written into this location clears the
maximum program scan exceed counter, the lost partner counter, and the
lonely primary backup state counter. After the processor has read the non-zero
value, it will clear this word. This feature works for both the primary and
secondary processors, but will only work in Run mode.
Qˆiyvph‡v‚Ã &'$%$!#ÃAri…ˆh…’Ã
4-7
(((