8/6/2011 3:56 PM | |
Joined: 10/7/2005 Last visit: 4/18/2024 Posts: 3003 Rating: (1046)
|
Hello nandy70 since you are talking about a 240 Byte limit, I presume you use the CP342-5 as a DP Slave, correct? If so, there is nothing you can do to increases this I/O limit (the Profibus DP standard allows for 244 Bytes of I/O data per DP Slave, the CP342-5 does only allow for 240 though). There afewways that I can think of to increase the amount of data exchange: 1.) Mutiplex the data by implementing a "header" in the I/ O area and writing a bit of code around it to handle the data transfer. You won't need any new hardware for this, but it does require someprogramming effort on the S7 as well as the DCS side and you'll find an example in THIS link (it is for FDL data transfer, but the principle of thistype of comms multiplexing is universally applicable). 2.) Add another CP342-5 to the S7 which will give you another 240 Bytes of data (you'd use seperate FC1/2 calls and send/receive DB's for this). 3.) If your S7 has an unused onboard DP port, configure it as a DP Slave and link it to the same Network as the CP342-5 to give you another 244 Bytes of I/O data exchange. 4.) If your S7 has anonboard DP port that is already used as a DP Master, add a DP/DP coupler to link and link it to the same Network as the CP342-5to give you another 244 Bytes of I/O data exchange. I hope this helps |
Cheers |
|
8/8/2011 10:17 AM | |
Posts: 5 Rating: (0) |
Very helpful comment |
This contribution was helpful to1 thankful Users |
8/9/2011 11:43 AM | |
Joined: 10/7/2005 Last visit: 4/18/2024 Posts: 3003 Rating: (1046)
|
Hello Hulzhex already answered the LADDR part of your question, so here are just a couple of additional hopefully helpful links:
How do you configure a CP342-5 as DP slave to a CP 342-5 as DP master? S7-CPs Manual/ Part B1 / Part Description of the CP 342-5 As for this:
You can use the CPU's DP Master port and create a DP link to the DCS's DP Master by using a DP/DP coupler (see also item 4 of my previous post). It'll save you money (DP/DP couper is a fair bit cheaper than a CP342-5),rack space in your S7-300 and is arguably easier to configure (you'll fidn the manual for it HERE). Last but most definetely not least, you'll find plenty of additional info and Forum related Q&A's for both subjects with a search at https://support.automation.siemens.com I hope this helps |
Cheers |
|
Follow us on