This is an excellent video, I went through so many video on internet but could not understand the basic concept behind Profibus DP and Profibus PA . It help me to understand the concept of Profibus and also helped to understand the difference between Profibus PA and Profibus DP.
Hi Sachin, Thanks a lot for your kind compliment! We are always extremely happy to hear such positive feedback! If you ever have any questions, feel free to reach out to us. Happy learning!
Outstanding video. It would be even better if you could add real life examples of explained topics. Nonetheless, the absolute best channel about automation on youtube.
Realpars videos were great in helping me prepare for my interview, and I got the job. Kudos guys. Q: The cables from the sensors or transmitters to the PA Bus, are they also profibus PA cables?
Great news on your interview! Best of luck in your new job! Yes, Profibus PA cables are used to join individual sensors to the PA bus as well as make up the bus itself. The cable is single pair 18AWG stranded tinned copper, insulated, shielded cable with PVC outer jacket, usually orange in color.
Profibus PA is used to communicate directly with the device (transmitter, sensor, etc.). The data resides in the device and is transferred to/from the PLC without having to go through a remote I/O subsystem (interface card, analog and digital I/O cards, etc.). This simplifies the cabling and structure for communicating with the field devices.
Thanks for your comment! That would make for a great topic suggestion, I will happily forward this to our course developers. Thanks for sharing and happy learning!
Hi... real pars is doing great job. My doubt is about the protocol and physical cables. Like modubus RTU, TCP/IP, RS 485, 422, foundation fieldbus, profibus, Ethernet, profinet etc.. Among these which one is protocol and which one is physical cable. Thank you.
Dear team, Please upload a video on profibus and profinet communication with details on gsd files, profibus configuration tools, configuration database file to be loaded to master controller, communication testing softwares, hardware accessories and demo testing.
Thanks for your topic suggestion, Muhammad! Great suggestion. I will happily go ahead and pass this on to our course developers as a possible topic suggestion.
Thanks for the good video, however some comments: When you explain in profibus DP the sensors are connected to the I/O, you should clarify what kind of connection, e.g analog 4-20ma?. When using profibus PA, same type of sensors can be used?
4-20ma transmitters develop an analog signal by varying the current along the wire connected to the analog input card. ProfibusPA is completely different. ProfibusPA and 4-20ma are not compatible. For ProfiBus PA, you will need a different transmitter, cabling, power supply and communication card. ProfiBusPA is a digital communication protocol, not analog like 4-20ma. Each transmitter is considered a node and is configured with software provided by the host controller. ProfibusPA devices can communicate much more data than the single PV variable of analog transmitters, incuding PV, totalizer values, sensor health, and configuration parameters (like range and alarm setpoints),
Is PROFIBUS and foundation fieldbus network follow same strategy to transfer data from field devices ? What’s the basic difference between them ? By the way kudos to entire team. Never watched a video which is as easy as this to learn about automation and plant control.
In the video, you said, 'We move the Inputs & Outputs from Control Room to the field, by this you mean that in this Profibus PA setup, we move the Input/Output Modules/Cards to the field near the sensors...right?
Yes. I can use a variety of devices to connect sensors using Profibus near the location of the sensors, and then connect one cable back to the PLC rack. This saves space, cable, and wiring costs.
@@realpars So you mean in such setup, the Input/Output PLC Modules(Cards) are not present in the PLC Rack in Control Room but are present somewhere in a JB in the field near the concerned sensors, right? Please confirm/clear my ambiguity.
Really I love Real Pars videos, I learn a lot of automation and I can apply this knowledge in my job as programer in OEM factory. I have a question, if I use Profibus PA do I need Profibus PA sensor/actuator or simply can I use the standard NPN/PNP sensor/actuator? And what is the maximun distsnce between the Profibus PA coupler with the master and with the I/O? Thanks a lot!!
Yes, your sensor has to specified with and have a Profibus PA interface card. The maximum total length of a Profibus PA segment is 1900m, but if it has drops or spurs, they can only be 30m in length each. The spur length must be considered in calculating the total segment length. Practially, I limit the segment lengths to less than 1000m to avoid any potential problems. For installations in hazardous areas, 1000m is the limit but other considerations also have to be made for power. All Profibus cables must be run in isolated, grounded conduit or segmented, grounded cable trays, at least 18 inches from any AC voltage or inductive circuits to avoid electrical interferences.
No I/O modules are required. The ProfiBus PA cable is dropped and connected to each device. Passive junction blocks can be used to make it easy to connect several blocks locally, but these are not I/O modules since they are passive and not active (no configuration or memory).
Thank you for the simple explanation.. I am wondering if the Profibus PA is an replacement of HART protocol and what is the difference between these two protocols.
Yes, HART and ProfibusPA are very similar in the type of data that is provided between the sensor and control system. HART is somewhat simpler, since most analog sensor now come standard with HART and most analog I/O cards provide a HART interface. HART can be used regardless of the communication protocol used by the Remote I/O subsystem. ProfibusPA must use a linking device to transmit data to/from the sensors as well as 24VDC power. HART uses loop power from the control system analog cards.
With Profibus PA, you are communicating directly with sensors, valves, etc., and do not require separate I/O cards. Each device has the capability to provide many values for configuration, monitoring, and control.
@@realpars but how does it differentiate between the sensors on a PA bus? Does the sensors have some sort of ID? should we use some different kind of sensors on a PA bus?
Hi Keith! Great to hear that you have been directed to RealPars! We have a course library filled with over 400+ PLC Programming course videos. Our course library is specifically designed in a way where it provides all the tools needed for beginners to evolve into an advanced level through our hands-on courses. Feel free to have a browse through our course library to see which topics we cover at the moment. bit.ly/30ZrxWq Additionally, we have a free course on PLC Hardware bit.ly/2XnnUrF Hope this helps! If you have any questions, feel free to reach back out over here or at hello@realpars.com
Thanks for awesome video...please make one video on PDM ,how we can configure sensors parameters on simatic manager or already have plz share link.. thanks
Thanks for the knowledge sharing.... Some questions...Does that means the same software configuration is used in both protocol...? The sensors or transmitter used are they the normal ones found in the field or they are specially made for this Profibus-PA network (the port that's why I asked)....?
The sensor needs to have the electronics to be able to interface to ProfibusPA. Modern sensors/transmitters are able to be specified with a number of different interface cards installed. If your plant uses ProfibusPA, then the sensors/transmitters need to be purchased with ProfibusPA interface cards. Your sensor electronics need to match your instrument bus type. ProfibusPA and ProfibusDP have different data packet structures and baud rates for communication. TIA Portal can be used to configure many aspects of each protocol, so although the front-end may look similar, the packets used in communication are not.
Thanks for your support, Pranay! Our technical team is happy to answer any questions related to our course videos. Please, leave those in the comment section of that specific video. Happy learning!
Typically a transmitter or other interface electronics is used to connect the sensor/device to the PA bus. You must have a Profibus-PA enabled connection/interface to place a sensor on the Profibus PA segment.
Profibus PA has a data transmission rate of 31.25 kbit/s. the speed of a Profibus DP network is selectable at the master to run at speeds between 9.6 kbit/s and 12 Mbit/s. A particular speed should be chosen for a network to give enough time for communication with all the devices present in the network. I find that Profibus DP is most stable at speeds of 500 kbit/s and 1.5 Mbit/s.
I would need to know the specific model o the encoder to say exactly, but a blinking red with steady green LED usually indiates the encoder is ready for operation but not activated by the master (e.g. incorrect address configured).
Buenas tardes, gr por el vídeo, pero este me generó algunas dudas: Que voltajes manejan y que tipo y cantidad de información envía cada uno, los cables son iguales o que diferencia tienen?
Gracias por su pregunta. Primero los cables son diferentes. Debes utilizar un convertidor de DP a PA como mencionamos. Utiliza un cable DP antes de su convertidor y luego, dependiendo de sus dispositivos, debe usar el cable recomendado como se menciona en las especificaciones del convertidor y sus dispositivos, que debe ser un cable común. Puede agregar fibra óptica según sea necesario para sus dispositivos y convertidores adicionales para la fibra óptica. Los vendedores pueden proporcionarle información. Aquí te dejamos un enlace para tu aprendizaje. us.profinet.com/ cuando llegue al enlace, elija su ubicación con su idioma. ¡Feliz aprendizaje de REALPARS!
Thank you, Lawal! We have the following two subscription packages, which will both grant you full access to our complete course library (400+ video courses): - Monthly subscription package $19.99 a month - Yearly subscription package $119,- ($9.99 a month) billed once You can subscribe through the following link bit.ly/2IpeCp3 Hope to see you joining the RealPars familiy soon! Let us know if you have any questions. Happy learning!
This channel is one of its kind, thank you for your quality content. What kind of Profibus am I dealing with when I have many peripherals connected in a daisy chain scheme?
Both Profibus DP and Profibus PA can be connected as a "daisy-chained" bus. However, it more likely that Profibis DP is connected in this manner, since Profibus PA usually uses passive connection blocks to connect to the individual instruments, but even then, the blocks are daisy-chained one to another. If you are inspecting an existing installation, purple cable is most often used for Profibus DP and orange cable is most often used for Profibus PA. Profinet, an industrial ethernet protocol, is not daisy-chained and typically uses blue cabling.
Hello I have one question when profibus PA was used input modules of the PLC were removed. So where exactly are they now? Are they in control room near the PLC or in the segment coupler? Or near the sensors?
ProfibusPA is a bus protocol that gathers data from the nodes (sensors) attached to it. There only needs to be a Profibus-DP/PA linking device to join the PLKC to the ProfibusPA segment. There can be many Profibus PA segments attached to one PLC. Each linking device provides the same function as the I/O rack and cards in a traditional installation. The thing I appreciate is that bus networks such as Profibus PA eliminate a lot of I/O panels, saving cost and space.
Yes and no. Each protocol has a specific way that it interacts with the device they are connected to. ProfibusPA is used mainly for motors, drives, scales, etc., that regularly receive commands (start, stop, tare. etc.). These devices may have setpoints or feedback parameters that are analog in nature (integer values, etc). ProfibusPA is constructed around process transmitter data, with many floating-point values and slower update times (250msec) than typically is used for Profubus DP (50msec updates). The cards used in DP and PA devices are quite different and are constructed to handle the specific interfaces.
When we removed PROFIBUS-dp and put a unified cable PROFIBUS-pA, how does the PLC know from which sensor this signal is, because all the signals are in one cable?
Profibus PA communicates much the same way as Profibus DP -- via telegrams (data packets). In the header of each data packet is the node number from which the data came. The node numbers are unique on a Profibus PA segment for each device (sensor).
Except cabling efficiency what other benefit profibus PA provides over profibus DP? At what number of devices we should shift from profibus DP to profibus PA. Next, how much is the cost difference between the two setup for a given number of field devices?
Profibus PA allows for a larger array of data to be queried and set in the device as compared to Profibus DP. Profibus PA is used to connect transmitters, actuators, and other analog devices to the network. There is a way to install Profibus PA in an intrinsically safe manner, whereas there is not with Profibus DP. Profibus DP is a faster protocol and is well suited for digital devices like motors.
Great question! The process varies depending on the specific programming software you're using. Take, for instance, Omron, Allen Bradley, Siemens, and others. Explaining the intricacies within my response would be quite an information overload. However, I can certainly share that when you're working on programming your network, the software handles the addressing details. To delve deeper, I'd recommend checking out this informative resource on Siemens. It provides an excellent explanation and more in-depth information that might just answer your queries. Here's the link: support.industry.siemens.com/cs/document/22729270/how-do-you-configure-a-profibus-pa-network-in-step-7-?dti=0&lc=en-US Happy learning!
What are the pros and cons of using Profibus PA instead of ASi-bus? In my industry we rarely use PA but ASi is almost standard when it comes to field bus.
Profibus PA is a better choice for connecting analog transmitters, since Profibus PA can transmit larger block of data. Profibus PA installations are more costly than ASi installations on a per device basis. ASi is superb at interfacing digital devices to the PLC or DCS. As with any fieldbus, pick the one that meets your sensor interface needs at the price you are willing to pay. Obviously, once you have an installed base of sensors, it is likely that you will want to continue with that approach. Both Profibus PA and ASi require a master card and compatible interface cards at the device level. ASi has the advantage that the trunk cable does not require a terminator.
Thank you for all your videos, I have one question on this one, though: Couldn't we have created profibus DP capable sensors instead of creating the Profibus-PA? If not, what's the main limitation?
The way that data is stored and communicated by Profibus PA and Profibus DP is fundamentally different, both in the size and scope of the data transmitted and in the transmission method. Profibus PA is polled and Profibus DP works on a telegram method of data request. Profibus DP is simpler and communication rates can be set over a range of speeds. depending on a number of factors. Profibus PA runs at a fixed speed and is used to communicate more data (transmitter configuration and process data) at regular intervals.
@@realpars Thank you very much, I'll look further into the protocols, then. Your answer was on spot and very efficient. Frankly I wasn't expecting to be answered on a 1 year old video, that was a good surprise, congratulations for your awesome job.
it's easy to connect a siemens plc or a scalance with profibus, but what about a sensor? how does a sensor connect to profibus? for example a thermocouple probe?
A sensor needs to have a Profibus interface built into the sensor. Typically, for these sensors, this will be Profibus PA. Profibus is a 2-wire system that has special connectors for use with Profibus PA sensors. Usually, an M12 connector is used. A thermocouple probe would not connect directly to Profibus. It would need to be connected to an RTD card in the PLC system or be connected to a transmitter that has a Profibus PA interface.
what kind of cables do we need between the sensors and the dp I/O and what kinda of cable do we need between the sensors and the Segment Coupler and how many sensors can we connect on a single segment coupler? Thanks
Hi Kholio, Thanks for your comment! This would make for some create new video courses. I will happily pass this on to our course developers for possible future video courses. Thanks for sharing and happy learning!
Profibus requires an external 24VDC power supply and a Profibus DP master, like a CP343 card in a PCS7 system. The data transmission is controlled by the master at a configurable baud rate. A ProfiBus system uses a bus master to poll slave devices distributed in multi-drop fashion on an RS485 serial bus. Data streams are parsed by packets according to the GSD file that defines the data string for a particular device. A packet can have up to 244 bytes.
Hi Bhushan, Thanks for your comment! You are right, we have recently upgraded our learning platform. This optimisation includes the following highly requested features: * Video speed adjustment * Auto-play option * Reviewing your own progress * Free Certificate of Completion for each course * Add trackable course completion certificate to your LinkedIn profile * Organised course structure * Admin options for enterprise accounts to view employee’s progress We are happy to bring you these new improvements which will grant an even better learning experience, as a result we had to decide to no longer support the RealPars App.
Great Video guys, I put some really big control systems in about 20 years ago using Omron PLC's with Profibus DP cards links to Profibus PA segment couplers and ASi masters(for digital IO). This was a huge success for us cutting down the control system design and installation massively. I moved on after that and since then have not worked with Profibus. My question is, I am looking at putting forward a control system using Profibus with Rockwell PLC hardware but wonder if its best to use the same conjuration I was using 20 years ago or should we be looking at Profinet? Quite how this changes things I am unsure of .Does instrumentation connect back to the PLC via some kind of gateway and does it power instruments as PA does.
Profinet is more "modern" but ProfiBus DP will work just as well in most cases. Either way, with Rockwell PLC's you will need a gateway. ProSoft has a variety of gateways for every configuration (www.prosoft-technology.com/). I love the PLX31-EIP-SIE Ethernet/IP to Profinet/IE gateway for its speed, reliability and ease of configuration.
Yes, a segment coupler allows a Profibus PA segment to be connected to a Profibus DP segment, which is required to be accessed by the PLC's DP port. Profibus PA is designed to connect directly to the process sensors without the need for a remote I/O rack or interface.
