4/22/2018 9:38 PM | |
Joined: 9/27/2006 Last visit: 9/23/2024 Posts: 12282 Rating: (2685) |
Hello emoth; If you are trying to make one single network with a Profibus-DP master and 300 Profibus-DP slaves, it will not be possible. The Profibus standard is based on RS-485, and that limits the basic segment of Profibus to 32 nodes with a maximum of 126 noces distributed over 9 repeaters. At this time problems on the forum blocks me from uploading links or attachments. Please go to Profibus.com/Downloads and search for the System Manual for Profibus-DP. This document will provide the information you need on the limitations of your project. So you would need a minimum of 3 Masters with at most 125 slaves (say 3 networks with 100 slaves each, for example) and at least 4 repeaters per network, depending on the speed of the networks and the length of each segment. If you want to have our help to design such a collection of networks, we would need to know the type of master you will be using, the speed you want to run the network, the distance and number of slaves per segment... Hope this helps, Daniel Chartier Edit: Here is the link to the suggested document from Profibus.com: https://www.profibus.com/download/profibus-technology-and-application-system-description/ D.C. |
Last edited by: dchartier at: 4/23/2018 1:28:52 AM |
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4/30/2018 3:30 PM | |
Joined: 9/27/2006 Last visit: 9/23/2024 Posts: 12282 Rating: (2685) |
Hello emoth; Providing on the system and the programming software you plan to use for a project always makes it easier for us to help you out. Let's say you are using a S7-300 CPU with an integrated Profibus port (such as a CPU 315-2DP) programmed in TIA Portal (just for this example). The integrated Profibus port (configured as a master) allows you to setup one Profibus network, with up to 125 slave nodes. Note that you would also need 4 repeaters on that network, since a segment can only hold up to 32 nodes, and segments must be coupled with repeaters. For the remaining networks you need to add separate Profibus masters; this can be achieved using CP 342-5 communication processors, hich can be configured as Profibus-DP master or slave. However, there is a difference between the CP 342-5 and the integrated port: you must program special functions, DP_Send and DP_Recv, that will exchange data between the CPU and the CP 342-5, over the bacplane bus: What are the differences between an integrated DP interface of my CPU (e.g. CPU 315-2 DP) and the DP interface of the CP 342-5? https://support.industry.siemens.com/cs/ww/en/view/21628388 Here is an appliction example showing how you setup and program the CP 342-5 as Profibus-DP masters, using TIA Portal: In STEP 7 (TIA Portal), how do you configure an S7-300 PROFIBUS CP as DP master or DP slave? https://support.industry.siemens.com/cs/ww/en/view/109744374 If you need more help designing the project further, do not hesitate to come back to the forum and ask your questions. Hope this helps, Daniel Chartier |
This contribution was helpful to2 thankful Users |
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