Process Gateway IEC104 COT when writing on Internal Variables

[PhilippeVDT]

Hi,

I am working on a conversion project from Sicam 230 into Zenon Energy Edition.

I have a question related to the process gateway.

I have an internal variable in Zenon, Data Type = real.  This variable is routed in the process gateway, IEC104, TI = 50.

This variable is used as a set point value to be treated in Zenon.

A rema is connected to this internal variable.  In the rema, there is a condition triggering a function to execute a VBA macro.  In VBA the further treatement of the received value is handled.

The rema only triggers the Function in case the cause of transmission = 6.

Since I write on an internal variable, the COT cannot be used to trigger a function.  So my question is, how can I get the COT out of the command entering the process gateway?  It has to get in there, but it is not available on the internal variables (as far as I know).

Thanks for your support
Philippe

[ursulak]

A value of zenon variable, if received by zenon Process Gateway, has status bits and timestamp given by the driver of the variable, not by the zenPG. The zenPG pokes (writes) the received value to the driver and only driver then decides what status bits and time stamp this variable will have in zenon. A write value to an internal variable does not cause the COT status updates. Only drivers IEC870, IEC850 and DNP3 are supporting COT.

To detect the new value received via zenPG to some variable, you have to react on value change. In the reaction matrix there is a check box 'treat each change of value as new limit violation' but i'm not sure if this will trigger when the new command contains exactly same value as the previous. Try out.

In case of zenPG IEC870Slave and T50: when your macro is completed, you can set to the variable some value out of range of this particular T50 command, e.g. some negative value. As T50 are 'write-only', the zenPG IEC870Slave is not sending any ASDUs to the remote 870-master when the zenon value changes. Thus, while you are just expecting new command, in zenon in the meantime you can set in this variable any value you want and know that the remote 870-master will never send such value in a command.


 

[PhilippeVDT]

Hi Ursulak,

Thanks for the tip for the work around.  It is working.

Philippe

A value of zenon variable, if received by zenon Process Gateway, has status bits and timestamp given by the driver of the variable, not by the zenPG. The zenPG pokes (writes) the received value to the driver and only driver then decides what status bits and time stamp this variable will have in zenon. A write value to an internal variable does not cause the COT status updates. Only drivers IEC870, IEC850 and DNP3 are supporting COT.

To detect the new value received via zenPG to some variable, you have to react on value change. In the reaction matrix there is a check box 'treat each change of value as new limit violation' but i'm not sure if this will trigger when the new command contains exactly same value as the previous. Try out.

In case of zenPG IEC870Slave and T50: when your macro is completed, you can set to the variable some value out of range of this particular T50 command, e.g. some negative value. As T50 are 'write-only', the zenPG IEC870Slave is not sending any ASDUs to the remote 870-master when the zenon value changes. Thus, while you are just expecting new command, in zenon in the meantime you can set in this variable any value you want and know that the remote 870-master will never send such value in a command.