Change behavior of bus state changes regarding to IP stack handling

Profinet IO Device Firmware up to PNS V5.2.0.x will set the IP address of integrated IP stack to 0.0.0.0 when the Profinet protocol stack busstate is set to "off". When the busstate is again changed to "on" the expected IP configuration is restored.

This shall be changed as follows:

• when Profinet protocol stack busstate is changed from "on" to "off", the IP stack configuration shall be untouched
• When Profinet protocol stack busstate is changed from "off" to "on", the current IP stack configuration shall be checked. If it differs to the expected one, the IP stack configuration shall be changed. If the IP stack configuration matches the expected one, no configuration change shall be done for IP stac.

In addition the following behavior shall be implemented:

• when Profinet protocol stack busstate is changed from "on" to "off", the LLDP frames sent shall report the Profinet NameOfStation as ChassisID
  • former behavior was to report MAC Address as ChassisID
• when Profinet protocol stack busstate is changed from "on" to "off", RPC EndPointMapper shall be reachable
  • the RPC Server instance shall be closed so that no RPC based Profinet services can be used
• when Profinet protocol stack busstate is changed from "on" to "off", SNMP continues to work and delivers all valid information as good as possible
• When a ChannelInit is executed and a Profinet configuration to apply exists, the IP stack configuration of the new configuration shall be applied, regardless of the current IP stack configuration. Even applying the same parameters is valid.
• When a ChannelInit is executed and NO Profinet configuration to apply exists (e.g. HIL_DELETE_CONFIG_REQ was used upfront), the IP stack configuration shall be set to IP 0.0.0.0. This more or less deconfigures the IP stack.