Juniper E Series Hardware Manual page 121

Figure 52: SRP module LEDs
The primary SRP module illuminates the REDUNDANT LED only when the
NOTE:
SRP module detects that there is a secondary or standby SRP module online. The
standby SRP module monitors an activity signal from the primary SRP module to
determine its state; it does not shadow the operations of the primary SRP module.
If the standby SRP module detects that the primary SRP module is not active, it
reboots the system and takes control. (ERX-7xx/14xx models only)
Status LEDs
Status LEDs
Understanding Status LEDs to Troubleshoot
Chapter 10: Troubleshooting
! 103