Basler Electric BE1-851 - Manual (Page 141)

SECTION 7 • BESTlogic™ PROGRAMMABLE
LOGIC
Introduction
Multifunction relays are similar in nature to a panel of single-function protective relays. Both must be wired
together with ancillary devices to operate as a complete protection and control system. In the single-
function static and electromechanical environment, elementary diagrams, and wiring diagrams provide
direction for wiring protective elements, switches, meters, and indicator lights into a unique protection and
control system. In the digital, multifunctional environment, the process of wiring individual protection or
control elements is replaced with the entry of logic settings. The process of creating a logic scheme is the
digital equivalent of wiring a panel. It integrates the multifunction protection, control, and input/output
elements into a unique protection and control system.
BESTlogic is a programming method used for managing the input, output, protection, control, monitoring,
and reporting capabilities of Basler Electric’s digital, multifunction, protective relay systems. Each relay
system has multiple, self-contained function blocks that have all of the inputs and outputs of its discrete
component counterpart. Each independent function block interacts with control inputs, virtual outputs, and
hardware outputs based on logic variables defined in equation form with BESTlogic. BESTlogic equations
entered and saved in the relay system’s nonvolatile memory integrate (electronically wire) the selected or
enabled protection and control blocks with control inputs, virtual outputs, and hardware outputs. A group
of logic equations defining the function of the multifunction relay is called a logic scheme.
Several preprogrammed logic schemes are stored in relay memory. Each scheme is configured for a
typical protection application and virtually eliminates the need for start-from-scratch programming. Any of
the preprogrammed schemes can be copied and saved as the active logic. Preprogrammed logic
schemes can also be copied and then customized to suit your application. Detailed information about
preprogrammed logic schemes is provided later in this section.
BESTlogic is not used to define the operating settings (pickup thresholds and time delays) of the
individual protection and control functions. Operating settings and logic settings are interdependent but
separately programmed functions. Changing logic settings is similar to rewiring a panel, and is separate
and distinct from making the operating settings that control the pickup thresholds and time delays of a
relay. Detailed information about operating settings is provided in Section 4, Protection and Control.
Working with Programmable Logic
BESTlogic uses two types of logic settings: output logic settings and function block logic settings. These
two types of settings are discussed in the following subsections. Output logic settings are entered in
equation form and control the hardware outputs of the relay. BESTlogic function blocks are illustrated in
Figures 7-1 and 7-2. These are discussed in the following paragraphs.
Names assigned to inputs, outputs, timers, and protection and control elements represent the logic
variables in the equations. Tables 7-1 and 7-2 list the logic variable names and descriptions.
9289900990 Rev R BE1-851 BESTlogic™ Programmable Logic 7-1