Search FAQs

Why is my M580 not at right NTP time ?

----------------------------------------------------------------------------------------------------
Context:
- All CPUs are concerned (BMEx58x0x0x)
- CPU configured as NTP client (both IPs: IPA and IP Main)
- IP A and IP Main are not on the same subnetwork (IP A = 192.168.11.3/24 and IP Main = 192.168.10.1/24)
- but a router is only set on one of the both subnetwork (i.e. 192.168.10.254/24 )

----------------------------------------------------------------------------------------------------
Behaviour:
Randomly, on boot CPU phase, communication is starting with NTP server using IP A, NTP server is not reachable. => because router is only set for 192.168.10.x addresses.

----------------------------------------------------------------------------------------------------
Nota:
This boot phase and random behaviour are documented in "Modicon M580, Hardware Reference Guide" (ref. EIO0000001578) into chapter "Installing Modules in an M580 Rack"/"Services and Addresses"

SNTP client document screenshot

----------------------------------------------------------------------------------------------------
Troubleshooting:
To avoid NTP packet filtering from the router, we recommand to configure the router subnetwork mask to 255.255.0.0 (16) instead of 255.255.255.0 (24)

----------------------------------------------------------------------------------------------------
Appendix 1: Example of IP Main and IP A
IP Main and IP A example

----------------------------------------------------------------------------------------------------
Appendix 2: example of NTP server
NTP server example