Unit Dispatch

Please refer to the attached powerpoint slide as part of the general
explanation below.

The remote terminal unit (RTU) system monitors our high voltage equipment
status. This includes the telemetering and revenue equipment required to be
a Control Area. The RTU's provide information that is identical to both
utilities (Control Areas). We have used the L&G protocol on all of the RTU's
to date.

The Scada Management Platform (SMP) is connected to the unit control system
(DCS). The SMP passes the setpoint that the Energy Management Systems, (EMS)
Automatic Generation Control (AGC) application has calculated the required
setpoint ( dispatch) that is required to be meet by each unit. The local
operator has to place each units local control system to the remote status
for the setpoint to be accepted at the plant. We have used the ESCA Inter
Site Data (ISD) protocal on all of the SMP systems to date.

The SMP also provides us with an alternate data source which is required as
a Control Area.

Thanks.