Finisar Surveyor Filter States, Changing States Changing Filter Operation, GoTo Current State

Surveyor

User’s Guide

Filter States

States are used to group a set of statements. Since statement contain conditions and actions, states are a way to create a set of conditions and actions.

You can specify up to 4 states with THGm. You always start and stay in State0 until an action takes you to a different state. The hardware device stays in a given state until a condition is met which results in an action that changes the filter operation.

When a state change occurs, the next packet is evaluated by the conditions of the new state. A changed state will apply to the next packet received, not the

current packet.

In most instances, you will only need only one or two states in a filter. Here is an example filter showing three states:

STATE0

IF (DA=Santosh) GoTo State1

ELSE IF (DA=Yancy) GoTo State2

ELSE GoTo CurrentState

STATE1

IF (DA_IP_Filter1) Counter1; Capture; GoTo CurrentState

ELSE GoTo State0

STATE2

IF (DA_IP_Filter2) Counter2; Capture; GoTo CurrentState

ELSE GoTo State0

Changing States (Changing Filter Operation)

When you select a state other than the current state, a “GoTo” phrase will display as part of the statement in the Filter States Design window, showing the next state; for example GoTo State1.

To change the state based on the conditions in a statement, double-click on the state- ment in the Filter states Design window. For IF or ELSE IF statements, this brings up the Filter Design window. Use the Set Filter Actions and Custom Counters button in the Filter Design window to reach the Filter Actions dialog box. In the Filter Actions dialog box use the Change Filter Operation check box to select a state change. The Next packet go to state: pull-down box specifies the new state. Cur- rentState means stay in the state number that contains the statement.

Double-click on an ELSE statement to bring up a dialog to specify just the actions to take when this statement is reached. The GoTo phrase always displays for the ELSE statement, even if it's the current state. The default setting for the ELSE statement is

GoTo Current State.

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