Skip to Content

Register Login

Industry Online Support

Technical Forum

Navigation

S7-1200 Peer to Peer with GET (and PUT) TIA V11

Created by: Stockley at: 5/8/2012 7:41 PM (10 Replies)

Rating (2)

Thanks 3

Result pages:: |; 1 | 2; |

11 Entries

Entries per page: 10 | all

5/8/2012 7:41 PM	Rate (0)
Stockley Posts: 5 Rating: (2)	I am experimenting with the GET instruction with a view to reading a DB in a remote PLC, but can't understand the ADDR_x parameters. The ADDR_x parameter is of data type "Remote" but this data type is not explained anywhere. I seem to be able to setup the S7 connection in the GET properties and I can enter the address of the local DBwhere the data is towritten but I can't figure out how toaddress theremote DBthat isto be read. I thought this would be an easy way of doing peer to peer instead of setting up more formal communication packets but I feel like I'm beating my head against a wall. I have already found some threads and examplesrelating to using GET in a300 where the remote is a 1200 but this has not helped. Does anyone have an example of GET between two 1214s inTIA V11? ...or an explanation of the Remote data type?
Stockley Posts: 5 Rating: (2)
Suggestion To thank Quote Answer

5/8/2012 9:03 PM	Rate (0)
0_Einstein Diamond Member Joined: 7/7/2010 Last visit: 11/6/2024 Posts: 15385 Rating: (2443)	TIA Portal V11 SP2 will generate the connection ID for you. Look in the help for S7 Connections. Basically for testing, create a new project. Go to Devices & Networks in new project tree, select Device View. Drag 2 PLCs into the project. Now the magic happens as follows: 1. Select the 'connections' (instead of "Network" (see attached image). 2. Click and drag fromthe profinet port on cpu 1 to cpu 2's profinet port. 3. Connection is created, named, and given the id you need for the get / put. From there, treat the remote device as just an address you can access using the P#xx as per the help documentation examples. The downside is you can't easily connect up something unless it's all in one big project file. However, with the tight integration available, it is a small price to pay. Attachment S7-Connection.jpg (2068 Downloads)
	science guy
Suggestion To thank Quote Answer

5/8/2012 10:25 PM	Rate (0)
Stockley Posts: 5 Rating: (2)	Thanks for the response Huggy - the connection setup is what I figured out - that all made sense. The RD_1 pointer (Variant data type) seems be accepted by TIA and I've used the samepointer data type before with SEND_PTP instruction - the BUFFER parameter is a pointer to a DB, so I think I'm good there. The trouble I'm having is with the "P#.." addressing of the ADDR_1 (Remote data type) I don't really understand it. And I can't find any other examples that use the "Remote" data type.I don't understand how I get this to point to the DB in the remote PLC. In this application we currently have 10 PLCs in a single project (which is great) we plan to increase thisby another 4 PLCs and 4 HMIs whereone of these new PLCs is intended to monitor the others and have a rudimentary status display onone of the HMIs.
Stockley Posts: 5 Rating: (2)
Suggestion To thank Quote Answer

5/8/2012 10:57 PM	Rate (0)
0_Einstein Diamond Member Joined: 7/7/2010 Last visit: 11/6/2024 Posts: 15385 Rating: (2443)	Stockley Thanks for the response Huggy - the connection setup is what I figured out - that all made sense. The RD_1 pointer (Variant data type) seems be accepted by TIA and I've used the samepointer data type before with SEND_PTP instruction - the BUFFER parameter is a pointer to a DB, so I think I'm good there. The trouble I'm having is with the "P#.." addressing of the ADDR_1 (Remote data type) I don't really understand it. And I can't find any other examples that use the "Remote" data type.I don't understand how I get this to point to the DB in the remote PLC. In this application we currently have 10 PLCs in a single project (which is great) we plan to increase thisby another 4 PLCs and 4 HMIs whereone of these new PLCs is intended to monitor the others and have a rudimentary status display onone of the HMIs. The connection limit is 8 if I recall correctly (per plc). You will have to create a tiered master/sub-master/slave relationship to have more than 8 connected to one 'master'. Now as to the data type, they are both P#'s and should look virtually identical. For example, let's assume in PLC_1 DB10 is configured exactly like PLC_2 DB10 and you want to read the first 10 bytes of DB10 from PLC_2 and save it to DB10 in PLC_1. The pointers would be _exactly_ the same configuration (meaning you could copy/paste) from one to the other field for ADDR_1 and RD_1. If you have one right, it's the same for the other. Just change the DB # to match your needs. Please post your results and if there is something I am missing, please let me know as I did not actually try this beyond the connection portion. The get instruction help does not call it a "remote" data type, but instead calls them both Pointers to data, one local and one remote.
	science guy
Suggestion To thank Quote Answer

5/9/2012 2:47 PM	Rate (0)
Stockley Posts: 5 Rating: (2)	What you say is pretty much what I was expecting too - I though this would set itself up (the last time I did something like this was with TI505 PEERLINK, amillion years ago and that was too easy). I did make some progress though, I threw away the project I was applying this to and opened a new one withonly 2 PLCs. I created the sameDB in both PLCs andadded the GET instruction to oneof them and set up the connection as before.I was able to enter the ADDR_1 pointer using the form P#DB1.DBX0.0 Byte 1 and copied this to RD_1 and it seemed to accept that. So I now get no error indications and both programs compile.There isalsoa little bit of code in the remote PLC thatsets the bits of one of the bytes in the DB by input switches and reverse in thelocal PLC to lightup its outputs according to the transferred byte. Thiswas downloaded to the two PLCs but I get error code #1 on theGET instruction that seems to indicate that communication has not been properly established. Since this is a simple piece of code I may create fresh a project and start again... again. I'm still a little concerned about the difference between the data types of the two pointers. More later.
Stockley Posts: 5 Rating: (2)
Suggestion To thank Quote Answer

5/9/2012 4:37 PM	Rate (0)
0_Einstein Diamond Member Joined: 7/7/2010 Last visit: 11/6/2024 Posts: 15385 Rating: (2443)	Stockley What you say is pretty much what I was expecting too - I though this would set itself up (the last time I did something like this was with TI505 PEERLINK, amillion years ago and that was too easy). I did make some progress though, I threw away the project I was applying this to and opened a new one withonly 2 PLCs. I created the sameDB in both PLCs andadded the GET instruction to oneof them and set up the connection as before.I was able to enter the ADDR_1 pointer using the form P#DB1.DBX0.0 Byte 1 and copied this to RD_1 and it seemed to accept that. So I now get no error indications and both programs compile.There isalsoa little bit of code in the remote PLC thatsets the bits of one of the bytes in the DB by input switches and reverse in thelocal PLC to lightup its outputs according to the transferred byte. Thiswas downloaded to the two PLCs but I get error code #1 on theGET instruction that seems to indicate that communication has not been properly established. Since this is a simple piece of code I may create fresh a project and start again... again. I'm still a little concerned about the difference between the data types of the two pointers. More later. Maybe post a couple screen captures of the s7-connection screen (similar to my prior example), and your get block. I assume the block in RD_1 exists and you are using the subnet (I think mine defaulted to W#16#0100) for the connection id. See image for a 'successful' get configuration. It successfully compiled even with an invalid ID, so that is my guess. Attachment S7-GET_Block_Config.jpg (2109 Downloads)
	Last edited by: huggy_d1 at: 5/9/2012 5:15 PM -added pic- Last edited by: huggy_d1 at: 5/9/2012 4:44 PM science guy
Suggestion To thank Quote Answer
This contribution was helpful to 1 thankful Users Tomy Master

5/9/2012 6:52 PM	Rate (2)
Stockley Posts: 5 Rating: (2)	Success! Re-read the manual and realized that the DB needs to be a Standard DB. "Accessing data in a standard DB: An S7-1200 CPU can use either absolute addresses or symbolic names to address DB variables in a standard DB of a remote S7 CPU." Once I did this it started to work. (My attention span is pretty poorso I have trouble paying close attention to technical manuals) So now back to the actual project, I can't find in the manual where the limit of 8 active connections is stated although I know I read it. If this is truly the limit then I hope to get around it by daisy-chaining GETs through throough the network - messy but it might work. Looks like I can only add one attachment so I've zipped the screenshots - I have a zipped project too but it's about 2MB. Thanks for all your help. Attachment GET.zip (1241 Downloads)
Stockley Posts: 5 Rating: (2)
Suggestion To thank Quote Answer
This contribution was helpful to 2 thankful Users 0_Einstein Synyster Fox

5/9/2012 8:04 PM	Rate (0)
0_Einstein Diamond Member Joined: 7/7/2010 Last visit: 11/6/2024 Posts: 15385 Rating: (2443)	That's great! Thanks for sharing the screenshots. I might have a need for something like this at some point. I also set my TIA Portal up to default to standard DB access so I totally overlooked that fine point. It seems there is very little gain with symbolic access, at least for now.
	science guy
Suggestion To thank Quote Answer

6/11/2014 1:54 PM	Rate (0)
Narrator1 Bronze Member Joined: 3/25/2013 Last visit: 3/21/2019 Posts: 176 Rating: (1)	Question split into topicGET Function with client with PLC IP address and DB number of their PLC. With best regards, Narrator1

Suggestion To thank Quote Answer

10/2/2014 2:37 PM	Rate (0)
Min_Moderator Platinum Member Joined: 9/3/2014 Last visit: 3/13/2019 Posts: 4766 Rating: (122)	Follow upquestion published byandreww5680 is split to a separate thread with the subject S7-1200 convert a DB to " standard". Best regards Min_Moderator

Suggestion To thank Quote Answer

|

Share this page:

Share this page on...

Follow us on