When switches are interconnected the network will not fail completely even one if the connected link fails. Switch statement has the same functionality as multiple else if statements but it is more organized and easier to use.
Loop At Switch Lighting Circuits
What is a switch loop. The switch statement is used to evaluate an expression and run different statements based on the result of the expression. Switch loops every now and then an electrician mentions something called a switch loop. A loop executes the sequence of statements many times until the stated condition becomes false. Figure 1 2011 nec handbook the common method prior to the implementation of the 2011 nec code of physically installing a switch loop was to use standard 142 cable which contains a white and black colored wire. Unknown unicast multicast and broadcast. What is layer 2 switching loop in practical local area networking it is common that the switches are interconnected for redundancy.
A block of statements is a multiple number of statements which are inside a block. With this arrangement the top half of the duplex is controlled with the switch and the bottom half is always hot. The control statement is a combination of some conditions that direct the body of the loop to execute until the specified condition becomes false. The purpose of the loop is to repeat the same code a number of times. The switch statement is followed by a block of statements. A switching loop or bridge loop occurs in computer networks when there is more than one layer 2 osi model path between two endpoints eg.
In laymans terms a switch loop is another term for a wiring circuit created to connect a light fixture to a wall switch. A switch loop is created when power is fed to a light fixture and the hot wire is broken and extended to a light switch. Instead of pulling a cord every time you want to turn the light on or off you flip a switch or push a button to activate the light. Switched with a pull chain is converted to use a wall switch. A loop consists of two parts a body of a loop and a control statement. When does a switch loop occur.
The white wire on the switch loop is used to carry current from the source to the switch and it is marked with black tape or paint to label it as hot. The switch statement is an enhancement to the if statement. As explained above a switch always floods three types of frames. Switch is also called a selective structure. Normally the neutral or return conductor accompanies the hot conductor. If a switch receives any frame of these types it will forwards that frame from all of its ports except the port on which the frame arrived.
Multiple connections between two network switches or two ports on the same switch connected to each other. If you have multiple expressions that need to be evaluated in one shot then writing multiple if statements becomes an issue. The black on the switch loop runs from the switch to the top half of the receptacle. A switching loop occurs when more than one link exists between the source and destination devices. In this tutorial you will learn types of loops.
Gallery of What Is A Switch Loop
