Setpoint Access Security; Description; Setpoint Access Jumper; Passcode Security - GE 750 Instruction Manual

7 SETPOINTS

7.3 SETPOINT ACCESS SECURITY

7.3 SETPOINT ACCESS SECURITY

7.3.1 DESCRIPTION

Hardware and passcode security features are designed into the relay to provide protection against unautho-
rized setpoint changes.

7.3.2 SETPOINT ACCESS JUMPER

To program new setpoints using the front panel keys a hardware jumper must be installed across the setpoint
access terminals on the back of the relay. These terminals can be permanently wired to a panel mounted key
switch if desired. Attempts to enter a new setpoint without the electrical connection across the setpoint access
terminals will result in an error message. The jumper does not restrict setpoint access via serial communica-
tions.

7.3.3 PASSCODE SECURITY

The relay has a programmable passcode setpoint which may be used to disallow setpoint changes from both
the front panel and the serial communications ports. This passcode consists of up to 8 alphanumeric charac-
ters.
The factory default passcode is "0". When this specific value is programmed into the relay it has the effect of
removing all setpoint modification restrictions. Therefore, only the setpoint access jumper can be used to
restrict setpoint access via the front panel and there are no restrictions via the communications ports.
When the passcode is programmed to any other value, setpoint access is restricted for the front panel and all
communications ports. Access is not permitted until the passcode is entered via the keypad (for the front
panel) or is programmed into a specific register (via communications). Note that enabling setpoint access on
one interface does not automatically enable access for any of the other interfaces (i.e., the passcode must be
explicitly set in the relay via the interface from which access is desired).
A front panel command is available to disable setpoint access once all modifications are complete. For the
communications ports, access may be disabled by writing an invalid passcode into the register previously used
to enable setpoint access. In addition, setpoint access is automatically disabled on an interface if no activity is
detected on that interface for a period of thirty minutes.
The 750/760 PC Program, included with the relay, incorporates a facility for programming the relay's passcode
as well as enabling/disabling setpoint access. For example, when an attempt is made to modify a setpoint but
7
access is restricted, the program will prompt the user to enter the passcode and send it to the relay before the
setpoint is actually written to the relay. If a SCADA system is used for relay programming, it is up to the pro-
grammer to incorporate appropriate security for the application.
GE Power Management 750/760 Feeder Management Relay 7-
3
Courtesy of NationalSwitchgear.com