Flexlogic Operands - GE C30 Instruction Manual

FLEXLOGIC CHAPTER 5: SETTINGS
The switch element has direct hard-coded connections to the IEC 61850 model as shown in the logic diagram. This allows
remote open/close operation of each switch, using either CSWI or XSWI IEC 61850 logical nodes. IEC 61850 select-before-
operate functionality, local/remote switch functionality, along with blocking open/close commands are provided. Note that
the dwell time for the IEC 61850 trip and close commands shown is one protection pass only. To maintain close/open
command for a certain time, do so either on the contact outputs using the "Seal-in" setting or in FlexLogic.
5.6 FlexLogic

5.6.1 FlexLogic operands

For flexibility, the arrangement of internal digital logic combines fixed and user-programmed parameters. Logic upon
which individual features are designed is fixed, and all other logic, from contact input signals through elements or
combinations of elements to contact outputs, is variable. The user has complete control of all variable logic through
FlexLogic. In general, the system receives analog and digital inputs that it uses to produce analog and digital outputs. The
figure shows major subsystems of a generic UR-series relay involved in this process.
Figure 5-48: UR architecture overview
5
The states of all digital signals used in the C30 are represented by flags (or FlexLogic operands, which are described later in
this section). A digital "1" is represented by a set flag. Any external contact change-of-state can be used to block an
element from operating, as an input to a control feature in a FlexLogic equation, or to operate a contact output. The state
of the contact input can be displayed locally or viewed remotely via the communications facilities provided. If a simple
5-116 C30 CONTROLLER SYSTEM – INSTRUCTION MANUAL