LED Display Cascading Connection & Redundancy Configuration Full Instruction!

What is LED display cascading connection, and how to achieve it? This is a common question when we operate a big LED screen that is driven by several LED display controllers, in which put cascading into an important position, and when we need redundancy configuration.

Just follow us to read this simple and straightforward guidance, we believe you will learn something that is beneficial to your LED display projects and makes you a LED display expert!

As you may guess, we have to figure out what is cascading firstly. And we will use Novastar series as our examples, but do not worry, the logic can be applied to almost all other LED controller brands.

1. What Is LED Display Cascading?

Before we talk about this concept, let us clear up the basic LED control system structure which we have already discussed before in this article: LED display connection


As you can see, here is a control PC, a LED video processor to process video sources from PC (sometimes there is not), a LED display controller, and finally, LED screen wall made up of LED display cabinets. Besides, cables will be used to connect different parts of the structure.

We have mentioned cascading is necessary when we have several LED controllers for a LED display wall. Thus, the structure may be like this:

In this case, we have two LED display controllers for the screen as the loading capacity of one is not enough. There is only one USB cable from the control PC to connect these two controllers, which is obvious, and this phenomenon is what we call cascading. 

2. Why LED Screen Cascading?

Now, we have clarified the definition of cascading – using one cable to connect two or more controllers. However, one thing may be confused: why do we need LED screen cascading?

There are two main reasons for this, we will discuss them in detail next.

Reason 1: Unified control of screens driven by more than one LED controller.

Cascading can support us to send parameters to the whole screen through only one software and one computer.

Reason 2: Redundancy configuration

Under some situations cascading is necessary for people to achieve redundancy. And we will talk about it later including why we need redundancy, and how to finish it.

3. How to Complete Cascading Connection?

There are four methods to finish the LED display cascading connection. We will introduce them to you one by one.

3.1 Cascading by LED control card

We will take Novastar MSD300 and MSD600 as example. Five pin flat cables will be applied to connect J18 and J6 on cards to finish the cascading. 

For J18, it is a cascading out port, and J6 is a cascading in port, meaning you have to use J18 to connect the first LED control card with the control PC by the USB cable and make J6 connect the first control card with the second one.

cascading connection

3.2 Cascading by LED control box MCTRL300 or MCTRL600

For instance, we can use two MCTRL300 control boxes to do this job.

Actually, we will still use five-pin cables but the shape of this kind of cable is different which is round. Here will be UART OUT port and UART IN port on the frontal of the box, so it is easy to understand that you should connect the first LED controller with the control PC through UART OUT and connect this port with the UART IN port on the second one.

3.3 Cascading of Novastar MCTRL660

As you can see, we have UART OUT port and UART In port on the LED controller. The logic of connection is the same, but the shape of ports is not the same anymore – they are Ethernet ports, which means normal Ethernet cables should be used to do the cascading.

MCTRL660 cascading

3.4 Cascading of other Novastar LED controller series

These controllers include MCTRL R5, MCTRL 4K, ProHD series, and so forth. You can know exactly from the picture below that we will use USB cables to finish the cascading but not Ethernet cable. And the rule is as same as what we have mentioned for other situations above.

how to do led display cascading connection

At present, we have discussed four ways of cascading such as cascading through LED control card, MCTRL300 or MCTRL600, and Novastar MCTRL660.

Obviously, there are two directions for you to put emphasis on when connecting: (1) what kinds of connecting cables do you have to use? (2) what is the sequence of connection through “in” and “out” ports?

4. How to Check LED Display Cascading Successful or Not?

Here is one simple guidance for you to get:

a. turn to NovaLCT interface; b. if the number of the control system is 1, then click “View Details of Device”; c. make sure the number of devices is correct, for example, if there are two LED controllers, the number should be 2; d. or you should make sure there shows one port on the screen configuration interface.

led screen cascading

5. Redundancy Backup - Why Do We Need This?

Redundancy backup, a familiar term for engineers and customers with industrial experiences, often confuses novices. What is the meaning? And when do we need to do this? We will go into detail in this chapter in a direct and simple method.

You can easily get the structure of a control system if you have followed our posts about LED control system before so we will not say in detail again here.

The picture below shows a situation where Ethernet cable happens some problems. And the green part of the LED display screen can perform normal video sources from control PC, whereas the red part represents the black screen.

Therefore, we should apply for redundancy back to avoid such plight, which is caused by Ethernet cable problem, and finally lead to wrong display.

led display redanduncy

5.1 How Redundancy Backup?

So, how can we overcome it? In other words, how can we achieve redundancy backup?

Generally, we can solve this problem by introducing another LED controller which connects to the last LED cabinets of the screen. Hence, if there is any problem that happens on the main channel, we can still use redundancy channel to transmit a video signal to enable the normal display.

As you can see, after we do this operation, the whole screen part shows green, representing the LED display can show contents normally.

led screen redanduncy backup

5.2 How to Set up Backup in NovaLCT?

Situation 1: Small LED display connected with one LED controller who has enough available ports.

As shown in the figure, here is one Novastar VX4S connected with a comparative small LED board. Because there are four output ports on the VX4S, thus we can use output 1 as the main channel, and output 2 as the redundancy channel to connect with the last receiving card of this loop.

led backup

So, how to set up corresponding specifications on the software? We take NovaLCT as an example.

Software setting for backup of small LED display

First, you have to set up the right LED display connection on the screen connection interface. In the picture below, we highlight the sequences in number.

If you do not know how to do LED display connection, just click the link to turn to our detailed and professional guidance: NovaLCT Screen Configuration.

led screen display connection

And then, we will turn to sending card setting.

led display backup

First, we will click the button “Add”, and then there will be a pop-up window where we should fill in four numbers.

It is obvious that the number of primary controllers and number of the backup controllers should be one as we only have one VX4S for the LED display control system. 

However, a little difference here should be noticed that the serial number of the primary port is one, while that of the backup port is two. You can easily understand it because we use port two to connect the last receiving card and to form the redundancy channel.

Third, please choose the button “Add” to set the specification.

Of course, do not forget to click “Send” to send the information to sending card, and click “Save”.

Now, we have presented how to do redundancy backup for small LED displays. Next, we will talk about big LED screen.

Situation 2: Big LED display connected with more than one LED controllers that are cascading.

Because of the limitation of loading capacity, we use two VX4S LED controllers here. According to the content about LED display cascading connection we discussed before, it is apparent that these two controllers are cascading as they are managed by one USB cable.

Output 1 of the second VX4S is connected to the last receiving card of the first loop, and output 2 of the second VX4S is connected to the last receiving card of the second loop. Apparently, VX4S is responsible for the redundancy backup.

led display cascading

OK, now we have understood the basic physical structure, we can move on to the next topic – how can we set up backup when the screen is cascading?

Software setting for backup of cascading LED display

In the first place, we need to make sure the right LED display connection. Please notify the parts we highlighted in this chart.

Here is one point that should be notified – only set the configuration to sending card No.1 as we only configure the main channel here. And the configuration of the second sending card will be finished in the redundancy part.

backup and redundancy

Then we will turn to the setting of screen configuration:

led sending card setting

Here are some differences: first, we need to set the number of the backup controller as 2 because we have two LED controllers in the control system. And then, the number of the backup ports is 1 as we use post 1 of the backup controller to connect with the last receiving card of the first loop.

Situation 3: Big LED display connected with non-cascading LED controllers.

In the last case, we talked about cascading LED controllers – how to deal with their redundancy backup. And in the picture below, you can easily get the two controllers are non-cascading as there is no USB cable connecting them together.

In consequence, how to complete LED display backup under such situation?

non-cascading led controller

First of all, we should connect the screen in the right method. Just refer to the steps in the shown picture.

non-cascading connection

Please notice we should configure the primary sending card, and the Ethernet port number should be 2. 

After we finish the setting logically, do not forget to click “save to file” as we can configure the backup LED screen directly then.

led controller setting

Second, click “set as the primary”, and then click “save”.

Next, let us start the configuration of the backup LED controller.

non-cascading back up led display

Please choose the second controller on the screen configuration interface, then choose “Load from File” so the setting can be finished automatically because we have already saved the setting of the primary LED screen before.

non-cascading backup led display configuration

Now we are configuring the backup sending card, thus, please click “Set as Backup”, and then “Save”.

6. Conclusion

In this article, we talk about how to achieve LED display cascading connection & redundancy configuration in a quick and right way. Different situations of LED display redundancy have been discussed, and detailed guidance and screenshot have been provided. Hope this article can help you. If you have any problems or requirements, welcome contact us right now!