GESPEEDTRONIC™ Mark VI Turbine Control System

ple nodes based on the UDP/IP standard

(RFC 768). Data can be transmitted Unicast,

Multicast or Broadcast to peer control systems.

Data (4K) can be shared with up to 10 nodes at

25Hz (40ms). A variety of other proprietary

protocols are used with EGD to optimize communication performance on the UDH.

40 ms is fast enough to close control loops on

the UDH; however, control loops are normally

closed within each unit control. Variations of

this exist, such as transmitting setpoints

between turbine controls and generator controls for voltage matching and var/power-factor

c

control. All trips between units are hardwired

even if the UDH is redundant.

The UDH communication driver is located on

the Main Processor Card in the Mark VI. This is

the same card that executes the turbine application software; therefore, there are no potential communication failure points between the

main turbine processor and other controls or

monitoring systems on the UDH. In TMR systems, there are three separate processor cards

executing identical application software from

identical databases. Two of the UDH drivers are

normally connected to one switch, and the

other UDH driver is connected to the other

switch in a star configuration. Network topologies conform to Ethernet IEEE 802.3 standards.

The GE networks are a Class “C” Private

Internet according to RFC 1918: Address

Allocation for Private Internets – February

1996. Internet Assigned Numbers Authority

(IANA) has reserved the following IP address

space 192.168.1.1: 192.168.255.255 (192.168/

16 prefix).

Communication links from the Mark VI to

remote computers can be implemented from

either an optional RS232 Modbus port on the

main processor card in Simplex systems, or

from a variety of communication drivers from

the HMI. When the HMI is used for the communication interface, an Ethernet card in the

HMI provides an interface to the UDH, and a

second Ethernet card provides an interface to

the remote computer.

All operator commands that can be issued from

an HMI can be issued from a remote computer

through the HMI(s) to the Mark VI(s), and the

remote computer can monitor any application

software data in the Mark VI(s). Approximately

500 data points per control are of interest to a

plant control system; however, about 1,200