Siemens SENTRON PAC5200 - External Time Synchronization Via Fieldbus; Internal Time Synchronization Via RTC

9 Time Synchronization
9.4 External Time Synchronization via Fieldbus
214 SENTRON PAC5100/5200, 7KM5212/5412, Device Manual
E50417-H1040-C568-A1, Edition 03.2015
In these cases, SENTRON PAC5100/5200 is not synchronized anymore. The device uses the internal clock
(on milliseconds time basis) and the last valid drift. After the programmable time delay, the device reports "Clock
Error", see chapter 14.1.
Switching Back from the Secondary to the Primary NTP Server
While the device is synchronized by the secondary NTP server, it continues to cyclically poll the primary NTP
server. The device will only switch back to the primary NTP server if it receives correct time information and if
none of the criteria for Redundant NTP Servers are fulfilled anymore.
9.4 External Time Synchronization via Fieldbus
The time information can also be transmitted from the systems control via Modbus TCP using Ethernet inter-
face. When using the Ethernet connection, Siemens recommend, however, to synchronize the device from an
NTP server, see chapter 9.3.
When using the external time synchronization via fieldbus, the client should send a message containing the
time information to the device in 1-minute cycles.
9.5 Internal Time Synchronization via RTC
Besides external time synchronization, the internal time synchronization is also possible using the battery-buff-
ered RTC (Real Time Clock). SENTRON PAC5100/5200 features a quartz oscillator for this purpose.
The time offset of internal time synchronization is 86 ms/day maximum. Due to the reduced accuracy, RTC
should only be used in case of failure or unavailability of the external time synchronization.
NOTE
The Communication Manual SENTRON PAC5100/5200 provides information on the data format.
NOTE
The Communication Manual SENTRON PAC5100/5200 provides information on the data format.
NOTE
The Communication Manual SENTRON PAC5100/5200 provides information on the data format.