Siemens SICAM Q100 System Manual page 14

Communication
2.1 Communication Interfaces
Check for Twice Assigned IP Address
Serious problems can occur if the same IP address is assigned more than once in a communication network.
For this reason, an ARP request is sent to the own IP address during start-up of the device. If no response is
received from the communication network within 2 s, it is assumed that the IP address is not used in the net-
work.
Otherwise, the LEDs signal the multiple assignment of the IP address as an error message:
RUN ERROR ERROR
H1 H2
C C
Figure 2-2
The device is not integrated into the network in this case and a different IP address has to be parameterized.
NOTE
If the device is directly connected to a PC, the PC will need a longer period to be able to detect the connection
and therefore to receive the ARP telegram. In this case it may not be detected when PC and device have the
same IP address.
Reception of the Network Configuration from the DHCP Server
The network configuration can also be obtained from an external server. Using the DHCP protocol, the device
is integrated into an already existing network.
If the IP address 0.0.0.0 is configured, the device sends a query to the external DHCP server requesting the
network configuration immediately after booting. Having received the network configuration, the device launch-
es the Ethernet services.
If no DHCP server is available, disconnect the device from the network and start it using the default IP address
and subsequently assign a permanent IP address.
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Error Message: RUN - Flashing, ERROR - On, H1 and H2 - Any Status
SICAM Q100, 7KG95xx, System Manual
E50417-C1040-C522-A8, Edition 09.2020