FIBER SENSYS Fiber Defender FD348R, Application Note, Page: 21 / 31

21
Establishing Communication
As noted in the communication flowchart, the APU sends a platform status report (PSR) every
20 seconds and a ping response every 130 seconds in order for the system to identify the APU
and to determine whether to communicate with it. When a ping request is received, the APU
sends the handshake messages shown below.
Figure 22: Handshake messages