Navigation
Up to 9 IM158-4 CPU's Sending/geting data form/to S7-319 CPU
Created by: TEBANCH at: 5/21/2010 11:12 PM (4 Replies)
Rating 
Thanks 4
5 Entries
| 5/22/2010 5:15 AM | |
Joined: 10/7/2005 Last visit: 3/25/2025 Posts: 3042 Rating:
|
Hello TEBANCH GET/PUT are a great (and sometimes almost only sensible) choice when you must have unilaterally configured connections (i.e. connection is only configured in one PLC) or when the Partner PLC can only act as a Server for S7 communications and/or you only need to exchange small volumes of data (nor more than ~160 Bytes). In your casethough (onboard PN port of CPU319 and IM151-8 CPU), you can have bilateral configured connections,both can be a Server as well as a Client for S7 communications and you need to exchange ~ 1Kb of data. As such,allow me to only answer Q4 by saying that I would personally NOT use GET/PUT but instead use BSEND/BRECV. The extraprogramming effort for these compared to GET/PUT is minimal and it will save you the "breaking up" and multiplexing of the 1Kb of data into smaller chunks. And here are a few more supporting links just in case you don't have these yet: Which communication services are supported by CPUs with an integrated PN interface? How do you program communication blocks FB12 "BSEND" and FB13 "BRCV" for data exchange on the S7-300? Which types of connection/protocols do the S7-300/400 CPUs and the CPs support by default? P.S: You can NOT use FC5/6 (AG_SEND/AG_RECV) with the PN port, but FB12/13 (BSEND/BRECV) are essentially their counterpart for S7 communications. I hope this helps |
Last edited by: fritz at: 5/22/2010 5:27 AMadded P.S. Cheers |
|
This contribution was helpful to
|
|
| 5/25/2010 3:57 AM | |
|
Joined: 10/7/2005 Last visit: 3/25/2025 Posts: 3042 Rating:
|
Hello again TEBANCH
It will without problems, simply call all 8 (eight) BRCV's together every scan unconditionally.
Yes you can, everyone of the configured S7 connection is a "two way street", so you can have one BSEND in CPU "1" and one BSEND in CPU "2" running over one configured S7 connection(together with their corresponding BRCV calls).
You'd be just fine with this setup. The 319 allows 16 S7connections (out of 32 max allowable connections) and the IM151-8 allows 10 S7 connections (out of 12 max allowable connections). Note too that NetPro does check this and won't allow more if you try to configure more than what's allowed in either CPU. Let's assume that you have configured eightS7 connections in your319 (one connection to eachIM151-8) and you will have eightBRCV calls as well as eightBSEND calls in the 319: You will in this case consume halfof the total available S7 connections (8 out of 16) and half of the total available "communicationinstances"that the 319 is capable of (16 out of 32). Each IM151-8 will use onlyconsume 1 out of 10 possible S7 connection and only 2 out of 32 allowable "communicationinstances". I hope this helps and here are a few more links on this subject: Communication with SIMATIC S7 Selection Criteria for Networks and Services What are the system limits in an F CPU for safe bidirectional data communication via S7 Communication? (F-CPU comms specific, but still a "good yarn". more so for outlining the differences between "Total connections", "S7 connections" and "Communication instances"). |
|
Cheers |
|
This contribution was helpful to
|
|
Follow us on