Program blocks
5.2 Changing the IP parameters during runtime
CP 154xSP-1
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Operating Instructions, 12/2019, C79000-G8976-C426-05
Connection establishment and termination
Connections are established using the program block TCON. Note that a separate program
block TCON must be called for each connection.
A separate connection must be established for each communications partner even if
identical blocks of data are being sent.
After a successful transfer of the data, a connection can be terminated. A connection is also
terminated by calling TDISCON.
Note
Connection abort
If an existing connection is aborted by the communications partner or due to disturbances on
the network, the connection must also be terminated by calling TDISCON. Make sure that
you take this into account in your programming.
5.2
Changing the IP parameters during runtime
Changing the IP address during runtime
As of STEP 7 V14, you can change the following address parameters of the CP program-
controlled during runtime with T_CONFIG:
●
IP address
●
Subnet mask
●
Router address
Note
Changing the IP parameters with a dynamic IP address
Note the effects of program-controlled changes to the IP parameters if the CP obtains a
dynamic IP address from the connected router: In this case, the CP can no longer be
reached by communications partners.
Note
Requirement in the CP configuration
To be able to change the IP parameters program-controlled, the option "IP address is set
directly at the device" must be enabled in the configuration of the IP address of the Ethernet
interface of the CP.
