Siemens CP 1542SP-1, Руководство по эксплуатации

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Configuration
4.6 DNS configuration
CP 154xSP-1
Operating Instructions, 12/2019, C79000-G8976-C426-05
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Note
Ensuring a valid time of day
If you use security functions, a valid time of day is required. It is recommended to use the
NTP (secure) method.
Note
Manually setting the time of day during commissioning
If you use security functions or SINEMA RC, set the time manually during commissioning;
see section Commissioning the CP (Page 47).
4.6 DNS configuration
DNS server
A DNS server may be required when the module itself, a communications partner, or an NTP
or e-mail server, for example, should be reachable via the host name (FQDN).
When addressing a communications partner as FQDN, you need to configure a DNS server.
The IP address (IPv4/IPv6) of the communications partner is then determined via the
configured DNS server.
When using IPv6 addresses, make sure to configure the DNS servers accordingly.
4.7 Communication with the CPU
Validity: CP 1542SP-1 / CP 1543SP-1
You will find the description of the CP 1542SP-1 IRC in the relevant configuration manual.
Watchdog bit
● CP monitoring
The CP checks the connection with the CPU via the watchdog bit.
The CP transfers the bit to the CPU every 5 seconds and resets it in the next CPU
sampling cycle. The bit is not transferred in the event of connection faults. This signals
the connection fault to the CPU.
The PLC tag of the watchdog bit must be evaluated by the user program.