AC900 F SOE
Good afternoon , please could you support in the following questions?
Customer is thinking in installing AC900F , it is going to be connected to third party Scada System . Is it possible to have SOE functionality in AC900 F using Profibus DP communication ?
Nowadays we do not know the information about the secuence resolution but at the beginning it could be 5 ms ( we should ask to the customer) , Is it possible to achieve it ?
Also ,as we have mentioned above , if we connect AC900F/ Opc Server to third party Scada using the proper license and Scada get the values from AC900F / Opc Server , Is the Opc Server able to transmit less than 5 ms resolution it could be related to number of tags and attributes transmitted but it is possible to transmit faster than 5 ms which it allows to external system do something like SOE ?
Or if not could we use ModBus Tcp and , could it be faster or faster enough?
Is it possible?
Thanks for your support
Using a fielbus protocol like PROFIBUS DP(V1) or Modbus you cannot really be certain about the accuracy of the timing. You have several independent communication cyles running freely (not synchronized) from each other. There is the sample cycle on the I/O module itself, where the I/O modules sample the data from the inputs. You usually have filters active to suppress noise like 50 Hz filters, which create a delay.The I/O module communicates cyclically with the PROFIBUS Slave module in the cluster. The I/O slave communicates cyclically wirth the PROFIBUS Master on the fieldbus module FI 830F. There is an asynchronous I/O task, collecting the data from the fieldbus modules into the system memory and finally there is the task cycle of the application program and only then the time stamp gets applied. In the worst case you have to add all those cycle times / delays. We have seen delays of 20 ms by the PROFIBUS slave module alone. So 5 ms is not possible that way. You have to use dedicated hardware and software.
Freelance OPC Server can be set to deliver values with a 100ms cycle only
In Freelance you have 2 possibilities:
A) Use DDI 01 rack I/O. You can get 2 ms SOE with that. Problem is those modules are at the end of their life cycle, but you can still get refurbished parts
B) Use an external SOE recorder, which can be integrated into Freelance. Have a look here: http://www402.abbext.com/Freelance-2013-SOE_1-0_a5562.aspx