Overview Network Bridge

With this function block a connection to another controller is established. This allows several controllers to be merged into one project. For example, to connect several standalone controllers to a central visualization.

With a connection, not all variables are transmitted, but only those main groups which have been specified in the parameter Filter.


Outputs
ST
 Status
Status of the connection:
  • 0: Not connected
  • 1: Connected
  • 2: Connected and authenticated
  • -1: Network error
  • -2: Connection error (e.g.: IP address wrong)
  • -3: Authentication error (password wrong)
VB
 Connected
 1 when connected and authenticated otherwise 0.
TI
 Received
 Received telegrams
TO
 Sent
 Sent telegrams
WC Watchdog Counter Display Watchdog Counter. To monitor the connection, a telegram is sent cyclically to the client and the response is evaluated. When sending, the counter is incremented. If the counter does not change, there is a problem with the connection and the connection is reset.

Parameters
Filter MG
 In this parameter at least one main group must be specified as a filter. Only variables from this main group are transmitted. Several main groups can be specified separated by semicolon (";"). The filters are always specified without offset MG. Important: The filter does not limit the data actually transmitted over the network. Only the telegrams that are passed to the runtime / logics are filtered.
Offset MG
 Offset main group. When a variable is received, this offset is added to the main group, and subtracted when sending. When several controllers are connected, an individual main group can be defined for each controller via this offset; the main groups at the connected controllers can always remain the same.

For example, on the central controller the main groups 100,101,102 etc. are created, 100 is the first controller, 101 the second. On the connected controllers only the main group 100 is created. For the first controller offset 0, for the second 1 etc. is specified, so the projects at the connected controllers can always be the same.
Filter time Filter time in seconds. With this parameter telegrams are passed on with a delay. If an address changes several times within this time, only the last telegram is passed on. This parameter can be used if variables change very often in order not to overload the controller. Important: The filter does not limit the data actually transmitted over the network. Only the telegrams that are passed to the runtime / logics are filtered.
Direction
  • Bidirectional: The transmission takes place in both directions. With this setting, care must be taken that no loops arise, for example master sends a variable, slave changes it and sends, master changes and sends again etc.. Such errors can be recognized via the outputs TI/TO when an excessive number of telegrams is displayed here in a short time.
  • Send: Only variables are sent.
  • Receive: Only variables are received.
IP address
 IP address of the controller to which the connection is made. DNS names and port can also be specified, for example xy.dyndns.org:2000 if the forwarding of the default port is not possible.

Important: If controllers are connected over the internet, a stable connection must be ensured and the DNS names must always be able to be resolved, otherwise it may lead to  a blocking of the controller.
Password
 Password, this is the password that is specified when setting up a connection to the controller.


See also common parameters of all function blocks.