Setpoint Access Security - GE Multilin PQM Instruction Manual

KEYPAD
3.3.9 Setpoint
Access
Security
3–8
Courtesy of NationalSwitchgear.com
The messages are organized into logical subgroups within each Setpoints and Actual
Values page as shown below.
Press the /
MESSAGE MESSAGE
within that subgroup. Otherwise select the
display the next subgroup.
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P A G E H E A D E R
M E S S A G E
b) Computer Entry
When running EnerVista PQM Setup, setpoint values are grouped together on a screen. The
data is organized in a system of menus. See Chapter 6: SOFTWARE for further details.
c) Scada Entry
Details of the complete communication protocol for reading and writing setpoints are
given in Chapter 7: MODBUS COMMUNICATIONS. A SCADA system connected to the RS485
terminals can be custom programmed to make use of any of the communication
commands for remote setpoint programming, monitoring, and control.
The PQM incorporates software security to provide protection against unauthorized
setpoint changes. A numeric access code must be entered to program new setpoints using
the front panel keys. To enable the setpoint access security feature, the user must enter a
value in the range of 1 to 999. The factory default access code is 1. If the switch option is
installed in the PQM, a hardware jumper access can be assigned to a switch input. Setpoint
access can then only be enabled if the switch input is shorted and the correct software
access code entered. Attempts to enter a new setpoint without the electrical connection
across the setpoint access terminals or without the correct access code will result in an
error message. When setpoint programming is via a computer, no setpoint access jumper
is required. If a SCADA system is used for PQM programming, it is up to the programmer to
design in appropriate passcode security.
key when displaying a subgroup to access messages
and
MESSAGE
]
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S U B G R O U P H E A D E R
M E S S A G E
PQM POWER QUALITY METER – INSTRUCTION MANUAL
CHAPTER 3: OPERATION
keys to
MESSAGE
M E S S A G E W I T H I N
S U B G R O U P