GE RX3i User Manual page 94

Operating Sequence for CPU Clock Synchronization
The following diagram illustrates the sequence of events for setup and operation of a system that uses clock
synchronization.
Machine Edition
1
HWC + AUP file
GFK-2224Q
CPU
HWC + AUP file
2
User Logic:
Read SNTP Time Stratum
via COMMREQ 5001
3
User Logic:
- Choose ENET to use
for CPU time sync
- Enable CPU Time
Update interrupt
via COMMREQ 5002
Process interrupt
- Update CPU TOD clock
4
Process interrupt
- Update CPU TOD clock
Figure 44: Operating Sequence for CPU Clock Synchronization
Ethernet Module
ENET config + AUP
- enable SNTP protocol
- CPU time sync feature
Process SNTP time msg;
Lock onto time server
Update ENET TOD
Update time in shared memory
(CPU Time Update
interrupt is not enabled;
do not send)
Process COMMREQ 5002
Update ENET TOD
Update time in shared memory
(CPU Time Update
interrupt is enabled)
Send CPU Time Update
interrupt
Send COMMREQ Status
Process SNTP time message
Update ENET TOD
Update time in shared memory
(CPU Time Update
interrupt is enabled)
Send CPU Time Update
interrupt
January 2017
Chapter 5. Ethernet Global Data
SNTP Time Server
SNTP network time
SNTP network time
81