How can we reduce the Updation time of SCADA

[monto]

Hello Friends,

I have an application using cimplicity SCADA, where there are four devices connected to the sCADA, 1>-GE PLC 2>-Three PID controller in multidrop on modbus 2 wire 485.
It seems that the updation time for the scada is almost 3-4 seconds.
Can anybody suggest how to reduce the Updation time for Scada.

Thanks

Monto