GE DGP Series, Инструкция по эксплуатации

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DGP Digital Generator Protection System GE Power Management
1.4 OTHER FEATURES 1 PRODUCT DESCRIPTION
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1.4.12 REMOTE COMMUNICATIONS
Two RS232 serial ports permit the user to communicate with the DGP from an IBM PC-compatible computer.
One of the ports, a DB-25 (PL-1), is located on the rear of the case and the other, a DB-9 (COMM), is located
on the front plate of the MMI module.
A PC may be connected to the DGP with a proper null-modem cable, provided the cable length does not
exceed 50 feet. The PC can also be connected via interposing modems if it is physically remote from the DGP.
GE-Link software is required to communicate with the DGP. The capabilities and use of the software are
described in Chapter 10: GE-LINK SOFTWARE. Refer to Chapter 9: COMMUNICATIONS for details regarding
the required cables and proper connection.
When a connection to the host computer of a station integration system is desired, the following two physical
connections are possible:
• Standard hard-wire cables may be used for distances up to 50 feet.
• For longer distances it is possible to add an optional external adapter that plugs into PL-1 to provide a fiber
optic link between the DGP and the host computer. An isolated 5 V DC supply is internally connected to pin
11 of PL-1 to power this external adapter.
Cables and associated equipment can be connected to each port simultaneously. However, when one port is
active the other is effectively disabled. For instance, when PL-1 is connected to host computer of an integration
system, it is not possible to log into the DGP from the front port when the integration system is active. If PL-1 is
connected to a modem and the front port is connected to a PC using a null-modem cable, then the first port
that becomes active is given preference, and the other port is disabled until the first is released.
1.4.13 REMOTE CONTROL
By using the local MMI or a remote PC connected to the RS232 port, it is possible to selectively operate any of
the four trip output relays for remote control. The control action may include shutdown of the machine, field
breaker trip, main generator breaker trip, turbine trip, etc., depending on the equipment connected to the out-
puts. The controls described above are enabled or disabled by a hard-wired jumper located on the MMI mod-
ule (see Figure 3–4: DGP MMI MODULE on page 3–5). As shipped from the factory, this jumper is physically
present and the Remote Control is disabled. To enable Remote Control, the jumper must be removed.
1.4.14 PASSWORD PROTECTION
Passwords provide security when using the local interface (MMI) or during remote communications while run-
ning the GE-Link program. Two different passwords provide local MMI security for:
1. control operations (close trip-output contacts)
2. settings changes.
Three different passwords in the GE-Link program provide remote communications security for:
1. view and upload information
2. control operations
3. settings changes
Refer to the Chapter 8: INTERFACE for a description of MMI password usage, and refer to Chapter 10: GE-
LINK SOFTWARE for a description of GE-Link password usage.
1.4.15 REMOTE COMMUNICATIONS – MODBUS PROTOCOL
The RS232 serial ports can be used with an optional RS485 to RS232 converter. Refer to Chapter 9: COMMU-
NICATIONS for further information on Modbus communication.