Trane Engineered Smoke Control System Application Manual page 127

Communication watchdog
Figure 66. Determining overall communication status for the system
Finally, the FSCP Comm Fault LED is controlled. A sample TGP
fragment is shown in Figure 67. The FSCP Comm Fault LED is also
controlled by the lamp test function. If a lamp test is not currently
running, the FSCP Comm Fault is controlled by the overall
communication status of the system.
Figure 67. Control of the FSCP Comm Fault LED
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