How to Wire a Profibus Cable to a Profibus Connector
Profibus is a widely used communication protocol for Siemens industrial applications. If you did not purchase a pre-wired Profibus connection or one was not provided for your application, you made need to wire one yourself.
In this video we are going to discuss what tools are needed for wiring the Profibus connector as well as the different steps required.
We will talk about what the different layers of the cable are called and how to strip those layers to get to the core wires required for the connector.
Go ahead an watch this lesson to learn how to wire a Profibus connection cable.
Below are the links for the Siemens products we mentioned in this video.
Profibus Cable: https://mall.industry.siemens.com/mall/en/us/Catalog/Product/6XV18300ET20
Profibus Connector: https://mall.industry.siemens.com/mall/en/ww/Catalog/Product/6ES7972-0BA52-0XA0
Profibus Fast Connect Stripping Tool: https://mall.industry.siemens.com/mall/en/ww/catalog/product/6gk1905-6aa00
When you're going to connect your PLC to remote I/O or any other device in the field using the Profibus network, you need to make use of an RS-485 or a Profibus cable. But to be able to connect the cable to the PLC or any other device on each end of the network, you first need to connect the cable to a Profibus connector. In this post I'm going to show you how easy it is to do that.
Here I have a Profibus cable and a Profibus connector. We ordered this cable from the Siemens and if you're wondering about the order number, this is the order number that you can use to order the same cable if you need to use that in your Project. Just Google the order number and the link for the Siemens site pops up in the first few results.
Now this is the product information for the cable I'm currently using in this video. As you know, cables are sold by the length. As you can see here, with this order number, the length for the cable you receive will be 200 meters which is about 650 feet. So if you need a different cable length for your project, you may want to consider a different order number when placing your order. Now where can you find the order numbers for different length of this cable? For that you can click on this link here on the top of the page which says Profibus bus cables.
Here in this page you can see a list of order numbers for the same cable but with different lengths. For instance with this order number, the cable length will be 20 meters which is about 65 feet or with this order number the length for the Profibus cable will be 50 meters or 160 feet. So depending on the project requirements, you can select a different order number when placing your order.
I'm also holding a Profibus connector in my hand. This is the order number for this connector. Just as you did for the cable, you can Google this order number if you want more info on this module.
We will put a link below this video to the Siemens website for both the cable and the connector. Now let's see how you can connect the cable to the connector.
Here we have a Profibus cable that we are going to connect to our DB9 Profibus connector. In this video I am going to show you how to do this. The items that I am using for this task are a DB9 Profibus connector, a Profibus cable, a utility knife, a screwdriver, and diagonal pliers or wire cutters.
The Profibus cable is a shielded twisted pair. We describe the outside as the outer sheath, followed by a braided shield, a foil shield, an inner sheath, and 2 single core wires, one green and one red.
The first thing that I need to do is to strip the outer sheath or the purple plastic outer cover. I’ll measure about 2” of cable which is approximately 2/3rds the length of my index finger. I’ll begin stripping the outer sheath by carefully scoring the plastic with the utility knife. Under ideal circumstances, I would use a Profibus Fast Connect stripping tool to strip the Profibus cable but in a pinch, I’m using a utility knife. You may use that or any other appropriate tool that you may have available. I’ll cut around the entire sheath being careful not to cut too deep into the cable and continue scoring the plastic until I’ve have cut entirely through sheath.
Now that I have cut around the outer sheath completely, I need to make a cut from the scored area to the end of the cable. I carefully use the utility knife to cut the outer sheath from cut section to cable end ensuring that I don’t cut too deep and damage the single core wires.
I have the utility knife and cabling oriented this way and I am cutting away from my body to minimize the possibility of injury.
I will probably need to make a few passes in order to completely cut through the outer sheath. Once I think that I have cut through, I am going to try to remove the outer sheath.
If you are unable to remove it, go back and continue to cut until you can successfully remove the outer sheath to expose the next layer of cabling which is the braided shield.
In order to remove this layer I will use the wire cutters and begin clipping the braid at the cut end.
Once a small section of the braid has been clipped, it may be easier to gather the remaining braid to clip it near the stripped end piece.
Continue to clip the braid all the way around the cable until you have removed as much of the exposed braid as possible.
Once the braided shield has been removed, I’ll use the utility knife to score the foil shield to remove it. The foil is fairly easy to remove and won’t require much effort.
Once the foil is removed, you will see the inner sheath that is fairly rigid.
I will use the same technique that I used while removing the outer sheath.
I’ll cut around the entire circumference of the inner sheath until I expose the single core wires. Use more caution during this step as this is the last protection for the wires.
Once I have completed the cut, I remove the inner sheath to expose the wires.
As described previously, here we have two single core wires, one green and one red. Separate the wires slightly in preparation for placing them into the Profibus connector.
I’ll open the connector and you will see that the internals consist of two cable connection paths.
Above the cable opening holes in the bottom of the connector, you will see two plastic tabs. These tabs, when pressed closed, will pierce the wires sheaths as well as hold them in place.
While the connector is held with the cable holes at the bottom, I gently lift the plastic tab on the left to expose the wiring mechanism which will hold both of the wires.
Use caution so as not to break the tab while lifting. With the tab up, I’ll place the green wire in the left side of the mechanism and the red wire in the right side.
Once I have both wires in place, I’ll close the plastic tabs. I apply pressure to the tab to ensure that the wires are held firmly in place and the piercing spikes penetrate the wires sheaths.
I’ll grasp the cable and route it through the cable hole on the left side of the connector.
Once the cable is properly routed, I’ll close the connector and make sure that there is no interference caused by the cable.
I secure the connector closed with the embedded screw and my screwdriver. Make sure you don’t tighten the screw too much as this may break the connector.
Well that’s it, that’s all there is making a Profibus connection. If you found value in this video, be sure to like us and as always, feel free to comment below.
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