System description:

The ATG 854 is the level measurement device, connected with an ST3000 pressure transmitter and MTT 762 temperature transmitter, the ATG sends level, temperature and pressure information via the Enraf GPU protocol to the SmartLink passing by the FDI 877.It has 2 SPDT alarm relay outputs connected to the Junction Box to indicate the H and HH level.

The FDI 877 is a Field Display Indicator, it reads the information from the GPU to display all the measurements. it works In the Indicator and Fall-back mode which allows the FDI to keep displaying the measurements if the host is not requesting them anymore.It has 2 SPDT alarm relay outputs connected to the Junction Box to indicate the L and LL level.

The SmartLink is the interface between the ATG (GPU com) and the ENTIS XL (Serial com) in the control station.

The control room has the a pc working on ENTIS XL to display all the measurements and alarms in real time, also graphs that shows the progress of measurements in time and the alarm log.

The tank side indicator TSI 977:

The TSI 977 was planned to be an extra indicator connected to the ATG or the FDI. The ATG does not have the TSI output option in it, so the TSI cannot be connected to it. The FDI - which is not ordered yet- can connect to the TSI only in HTG mode (Instruction manual

877 FDI – page 7) , the problem is that in this mode the FDI is designed to read measurements directly from a pressure or a temperature transmitter and send them to the TSI to be displayed, and won’t be able to communicate with the ATG

Therefore, as a conclusion, the FDI cannot be connected to the TSI and The ATG at the same time or in the same mode, and the ATG cannot be modified (need to verify with the other ATG), so the TSI will not be used in this system.