Diagnostics; Plc Status Words - Control Technology 2500 Series Installation And Operation Manual

Display – Status Codes "4", "5", "6", "8", and "C" listed on the front panel of older 2500-RBC's are
not used. Rev 6.0 and newer 2500-RBC's use codes "A" or "E For diagnostic failures, they also
display a new code "a" to indicate the user has an incorrect module inserted in a configured slot when
50X Ignore Mismatch is disabled. A "b" indicates the RBC is inserted into the wrong slot.
Reset switch – the 2500-RBC does not include a reset switch.
RS232 port – the 2500-RBC includes an RS232 port, but communication with the PLC using this
port is not presently implemented. Future versions of the product may contain this feature.
Mismatch handling
When 50X Ignore Mismatch is disabled and a module is inserted into an empty slot, the 2500-RBC
ignores the inserted module and continues normal operation. The 505-6870 considers this situation a
mismatch and takes the base offline.
When 50X Ignore Mismatch is disabled and the wrong module is inserted into a configured slot, the
2500-RBC displays an "a", takes the base offline, and sets outputs based on the freeze jumper setting.
The 505-6870 displays a "2" and takes the base offline.
When 50X Ignore Mismatch is enabled and a module is inserted into an empty slot, the 2500-RBC
ignores the inserted module and continues normal operation. The 505-6870 displays a "2", ignores
the inserted module, and continues normal operation.
When Profibus is stopped from the PLC, the 2500-RBC displays a "3", sets outputs based on the
freeze jumper setting, and turns inputs off. The 505-6870 displays a "3", sets outputs based on the
freeze jumper setting, and leaves inputs at their last state.

2.10. Diagnostics

The 2500-RBC provides diagnostic information in the PLC available in status words and through
execution of the RSD instruction in the ladder logic.

PLC Status Words

NOTE: For more information on STW diagnostics, see the CTI 2500 Series® Programming
Reference Manual, Appendix A.
STW147:
This PLC status word records the number of times, since the most recent start, that the Profibus-DP
slaves have failed to respond to a request from the CPU. Each time communication is lost to the
2500-RBC, STW147 increments by 1. When there is a base mismatch detected by the 2500-RBC,
STW147 increments continuously.
STW03-STW09
CTI 2500-RBC Installation and Operation Guide V1.6
13