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yara
29th December 2014, 09:48
Dear support,

I have 2 process gateways running in to different servers using DNP protocol, I want to make it redundant (one gateway running at the same time, if field second should run).

Kindly please guide how to do that.

Thanks in advance and best regards.

yara
29th December 2014, 14:07
I am using DNP 3.0 over serial communication.

markclemens
12th January 2015, 11:04
Hi Yara,

With DNP3 over serial communication, I assume that you have a serial bus to which the master is connected and to which both the DNP3 process gateway as an outstation on the primary server and the DNP3 process gateway as an outstation on the secondary server would be connected. The DNP3 outstation on the primary server and the secondary server would have the same DNP3 slave address and therefore should not be running at the same time. Is this assumption correct?

You can realize this using the non-dominant network redundancy, zenon functions to start the process gateway and some comparison in the zenon logic.


If the primary server is started and the secondary server is not running -> start the DNP3 process gateway on the primary server

If the secondary server becomes the primary server due to failing of the primary server, -> start the DNP3 process gateway on the secondary server

If the secondary server running as the primary server fails -> start the process gateway on the primary server


Note, that this does not consider the scenario where the TCP/IP network connection between server / standby server gets interrupted while the runtime continues to run on both systems. In this case the secondary server would recognize a failure of the primary server and start the DNP3 process gateway on the secondary server, while the DNP3 process gateway on the primary server is still running.

To cover also this scenario, you could instead consider creating two different DNP3 masters on both the server and the standby server e.g. in the zenon logic, to monitor a second instance of the DNP3 process gateway on the other server as where the logic is running. Then when a communication loss is detected, set a local variable in the zenon logic to start the DNP3 process gateways from the zenon runtime through a limit function of the local variable.

Best regards,
Mark

yara
27th January 2015, 13:29
Thank you for your support,

The question here, using what i can write the conditions ( if server fail then run process gateway on standby server ) ?

best regards

markclemens
27th January 2015, 13:52
Hi yara,

You could use the zenon logic for such decisions. Or you could use variables of the mathematics driver in combination with a reaction matrix. Or you could use the API in the runtime.

Best regards,
Mark

junaid
2nd February 2015, 14:22
Dear Copa Data Team,

Could you please provide the steps and more clarify us about the following statement.?

To cover also this scenario, you could instead consider creating two different DNP3 masters on both the server and the standby server e.g. in the zenon logic, to monitor a second instance of the DNP3 process gateway on the other server as where the logic is running. Then when a communication loss is detected, set a local variable in the zenon logic to start the DNP3 process gateways from the zenon runtime through a limit function of the local variable.


Please provide a visual steps if possible.