Skip to Content

Register Login

Industry Online Support

Technical Forum

Navigation

Communicating over Profinet

Created by: defterGoose at: 12/10/2014 9:20 PM (3 Replies)

Rating (0)

Thanks 1

4 Entries

12/10/2014 9:20 PM	Rate (0)
defterGoose Posts: 2 Rating: (0)	Hello everyone, first time poster here. I'm putting together a project in TIA V12 using an s7-1200 PLC, HMI, and a stepper motor with integrated PROFINET drive. I'm pretty new to PROFINET and PLC programming in general, and I'm having trouble figuring out how to set data registers over the profinet bus. Basically the motor has I/O registers mapped to different drive functions, so for instance setting the register mapped to Move Relative requires a DInt type that tells how many steps to move; pretty simple stuff. I've loaded the GSM file for the drive into TIA and setup my network connections. I've also put tags in my PLC tag table that correspond to the different I/O registers. In the drive's device view it shows as the interface 128 bytes I (I address 68...195) and 128 bytes Q (Q addresses 1...128), so I've made tags such as: "Move Relative" \| DInt \| %QD50 I thought setting these registers would be as simple as using the WR_REC block in my Main ladder, but now I'm confused as to how one actually uses this block. It seems like I can set INDEX to be the tag for my relative move, but i cant figure out how to actually send this output a real value, for instance 10000. I've read all the documentation I can find on profinet and the WR_REC block and it's all about as clear as mud as to what I need to feed to the block inputs. And what is this WRREC_DB thing? Can someone please explain to me the basic process of sending data/setting registers over the profinet interface? I would appreciate it very much! Attachment TIA screenshot.jpg (490 Downloads)
defterGoose Posts: 2 Rating: (0)	Last edited by: defterGoose at: 12/10/2014 10:12 PM
Suggestion To thank Quote Answer

12/10/2014 9:34 PM	Rate (0)
0_Einstein Diamond Expert Joined: 7/7/2010 Last visit: 12/11/2024 Posts: 15491 Rating: (2456)	defterGoose Hello everyone, first time poster here. I'm putting together a project in TIA V12 using an s7-1200 PLC, HMI, and a stepper motor with integrated PROFINET drive. I'm pretty new to PROFINET and PLC programming in general, and I'm having trouble figuring out how to set data registers over the profinet bus. Basically the motor has I/O registers mapped to different drive functions, so for instance setting the register mapped to Move Relative requires a DInt type that tells how many steps to move; pretty simple stuff. I've loaded the GSM file for the drive into TIA and setup my network connections. I've also put tags in my PLC tag table that correspond to the different I/O registers. In the drive's device view it shows as the interface 128 bytes I (I address 68...195) and 128 bytes Q (Q addresses 1...128), so I've made tags such as: "Move Relative" \| DInt \| %QD50 I thought setting these registers would be as simple as using the WR_REC block in my Main ladder, but now I'm confused as to how one actually uses this block. It seems like I can set INDEX to be the tag for my relative move, but i cant figure out how to actually send this output a real value, for instance 10000. I've read all the documentation I can find on profinet and the WR_REC block and it's all about as clear as mud as to what I need to feed to the block inputs. And what is this WRREC_DB thing? Can someone please explain to me the basic process of sending data/setting registers over the profinet interface? I would appreciate it very much! If you have loaded your communications configuration, the best way is to transfer data cyclicly using a predefined or user defined telegram. This is configured in portal by adding the drive as distributed I/O, picking the appropriate telegram in the hardware pane (right side of portal), and dragging it to the distributed i/o area for your drive. That technique is far simpler to implement, and very fast. The only hard part is initial configuration. After that, it is very simple to read/write data since it is already set up in the telegram. If you are using a Siemens G or S series drive, this is most definitely the way to go. Other manufacturers also provide similar telegram access. If you need to access things like ramp rate and other very drive specific parameters, then acyclic communications using RDREC and WRREC is the way to go for Siemens drives. Are we headed in the right direction? Welcome to the Siemens forums.
	science guy
Suggestion To thank Quote Answer
This contribution was helpful to 1 thankful Users Kahl

12/11/2014 12:00 AM	Rate (0)
defterGoose Posts: 2 Rating: (0)	Thanks for the response huggy, hopefully with some assistance I'll be moving in the right direction sooner rather than later :) I'm attaching a screenshot that will hopefully facilitate what we're talking about. I don't think that the manufacturer has provided this "telegram", I can't find it in the hardware section (as you can probably see), and I can't find any reference to it online either. My guess is they haven't felt the need to author it for their siemens users? The telegram would be in the form of a .al12 file, yes? So, assuming that's not available, i should be able to write it myself yes? Would it be one of the PLC data types? As you can see, I've added one already. But I'm not exactly sure what needs to go in the type. Is it just a list of names and values that get passed? There seems to be no I/Q addresses in the type table. So how would I go about "sending" this telegram to the drive cyclically? And how would I change the parameters being sent in the ladder logic? For instance, if i wanted to set the "Move relative" drive register to 1000, and then x seconds later i wanted it to be 2000 instead? Would this type of application be better suited to all acyclic transfers? Or would i just be making 2 copies of the telegram, with different params in each one? As for acyclic transfers, I'm not sure what parameters need to be passed to the WRREC block, as you can see. I've tried the tags from the drop down for each input, and I get lots of errors. I think a lot of the issue here is my very weak understanding of the difference between I, Q, M parameters, what they do, where they are stored, etc. I'm coming from a C++/Python background so the DB storage and ladder logic schema is something that I'm very much still wrapping my head around. I assume there are plenty of analogs, but the terminology is different, and, to my mind, confusing :/ Attachment TIA 2.jpg (479 Downloads)
defterGoose Posts: 2 Rating: (0)	Last edited by: defterGoose at: 12/11/2014 12:06 AM Last edited by: defterGoose at: 12/11/2014 12:05 AM Last edited by: defterGoose at: 12/11/2014 12:02 AM Last edited by: defterGoose at: 12/11/2014 12:01 AM
Suggestion To thank Quote Answer

12/11/2014 6:27 AM	Rate (0)
William_B Posts: 5225 Rating: (1197)	Hi. The company that put their badge on this product might be helpful to you. I suggest you ask them for some information on how to link via Profinet. You might be lucky enough to get a sample program. Try [LINK]. If you could return with a sample program the Experts will be of much more help. Also.. For communications between drive and PLC a block memory is allocated. The data that flows out of the device is buffered through "outputs" and data flowing into the device is buffered through "inputs". This is a bit confusing as the inputs and outputs is not physically going outside.. it is in this case "virtual". But the program handle these as if they are real physical inputs and outputs. The term "telegram" is used to describe how the data is packaged. For example the first WORD in the package might indicate SPEED.. but it could easily have been a group of boolean commands. Only the supplier can tell you how the data is packaged so that you can write the program to translate the data into information. I ask you to do some footwork at the manufacturer for information that will be helpful to the Experts to assist you further You can also have a browse though the forum pages for descriptions on what the difference is between FC / FB / DB and so on - even better if you can find a Siemens rep. to give you a quick tour to what PLCs are about. PLCs are different than what you are know, but I have confidence that if you can do C, you can get a PLC up and running in a short time. Greetings.
William_B Posts: 5225 Rating: (1197)
Suggestion To thank Quote Answer

|

Share this page:

Share this page on...

Follow us on