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S7-412-3H profibus master

Created by: Thomp_123 at: 8/27/2010 3:19 PM (6 Replies)

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8/27/2010 3:19 PM	Rate (0)
Thomp_123 Posts: 11 Rating: (0)	Hi, I am programming a S7-412 redundant system with one remote I/O rack connected to the redundantprocessors through two IM 153 modules to twoCP443-5 modules. I have added the various OBs as mentioned in the manual, configured my hardware,configured mynetwork and written my program. So far everything looks OK. However, I have to connect my redundant system to a third party DCS system using the profibus Master ports built in to the CPU module. Can onyone show me where to find a good simple sample program for a Profibus master system? Something that shows what OBs are required, what hardware and network configuirations are required, and code to show how to read and write data to profibus slave devices. Is this profibus master set-up complicated by the rudundancy? My assumption is that only the primary CPU port will be active in this scenario... Thanks, Phil
Thomp_123 Posts: 11 Rating: (0)	Last edited by: Phil_123 at: 8/27/2010 3:22 PM
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8/27/2010 5:34 PM	Rate (0)
dchartier Grandmaster-Expert Joined: 9/27/2006 Last visit: 11/16/2024 Posts: 12294 Rating: (2691)	Hello Phil; To connect your I/O to a redundant S7-400H system, you have used a redundant ET 200M system (a pair of IM 153-2 with a special backplane). To connect a "single-sided slave", one that has only one Profibus-DP interface, to a S7-400H system, you will need a Y-Link, which is basically the same arrangement than your redundant IM 153-2 pair with an additional Y-Coupler. Once configured, it allows seamless Profibus-DP links to the slaves from the redundant S7-400H. One limitation is that the Y-Link is seen by the Profibus-DP redundant master as a single slave, so you are limited to the amount of data determined for a slave on Profibus: 244 bytes OUT/244 bytes IN, no matter how many slaves are behind the Y-Link... Here isinformation on the harware and configuration of the Y-Link for your perusal;you will also find links to the Y-Link manual and other info: Y-link structure FAQ: http://support.automation.siemens.com/WW/view/en/43688632 S7 CPU as single-sided slave (using Y-Link) to a S7-400H redundant system: http://support.automation.siemens.com/WW/view/en/19951154 Use it as a basis for your own application. Hope this helps, Daniel Chartier
	Last edited by: dchartier at: 8/27/2010 5:36 PM Last edited by: dchartier at: 8/27/2010 5:35 PM
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8/30/2010 12:30 PM	Rate (0)
Thomp_123 Posts: 11 Rating: (0)	Hi Daniel, Thanks for your reply! I still have some questions though. I have attached a zip file containing screenshots ofmy hardware set-up and the netpro set-up for reference.How doI set-up my system to communicate with profibus slave devices over the redundant profibus connections "profibus(1)" and "profibus(2)". Can I configure the system to read/write to slave devices without knowing full details of those slave devices? (Could take weeks to get a straight answer). Regards, Phil_123 Attachment S7-400 screenshots.zip (248 Downloads)
Thomp_123 Posts: 11 Rating: (0)	Last edited by: Phil_123 at: 8/30/2010 12:32 PM
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8/30/2010 3:44 PM	Rate (0)
dchartier Grandmaster-Expert Joined: 9/27/2006 Last visit: 11/16/2024 Posts: 12294 Rating: (2691)	Hello Philk; You have an example for the setting up a Y-Link interfaceto a redundant S7-400H system in the FAQ suggested above. Even though the newer model of Y-Link uses a IM 153-2 pair instead of IM157 modules, the procedure is the same. So insert a Y-Link nbetween your redundant profibus lines (1) and (2), insert the GSD files for your slaves (you should be able to get them from your vendor directly, or through the manufacturer's website), and you can then start setting the up on the single-line Probifus starting at the Y-Link. I do not know how far you can go on these configurations, it will depend on the complexity of the slave and amount of data to be exchanged, but at least you can start, and have some questions ready foir the vendor when the equipment gets to site. Hope this helps, Daniel Chartier

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9/2/2010 1:33 PM	Rate (0)
Thomp_123 Posts: 11 Rating: (0)	Hi Daniel, Thanks again for your replies, but I'm going to show my lack of experience with profibus now... In the example given, the first profibus address entry in the CPU 315 table,"Master I Slave Q 1 B unit", is given the address"1". How do I use this in the ladder logic? i.e. how does the master CPU go about importing this profibus data into aDB file, or an individual "M" bit?Similary how do you go about setting bits within the output bytes? How do you address/access them in the ladder code? Regards, Phil_123
Thomp_123 Posts: 11 Rating: (0)	Last edited by: Phil_123 at: 9/2/2010 2:10 PM
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9/2/2010 2:41 PM	Rate (0)
dchartier Grandmaster-Expert Joined: 9/27/2006 Last visit: 11/16/2024 Posts: 12294 Rating: (2691)	Hello Phil; Profibus-DP was developped originally as a fast remote I/O system, and it mapped the modules of the DP-slaves to the digital and analog standard addresses of the DP-master. If you look again at the 4 modules in the CCPU 315-2DP slave that you have in your FAQ example, you will see that you have 1 byte of digital inputs, 2 bytes of digital outputs,4 bytes (2 words)of anallog inputs and 8 bytes (4 words) of analog outputs that you want to exchange with the DP-master. Note: the example uses German memonics, where A=Ausgang (output, Q addresses in English) and E= Eingang (input addresses in English) The first byte of digital inputs is mapped at master's input address 0, which means in your program you can access it as I0.0 to I0.7; the digital outputs can be used as Q0.0 to Q1.7; the analog inputs (2 channels) can be reached in the master's program using PIQW 512 and PIW 514; the 4 analog output words (channels) are mapped at PQW512, PQW 514,, PQW 516 and PQW518. Notice how the slave is configured, a little further down. It uses its own input/output mapping to create exchange areas that match in size and in reverse order the mapping of the master. Inputs to the master are outputs in the slave, outputs from the master are inputs in the slave. So the first slave module, named A0 is one byte of output (digital) that will be read by the master's 1 byte of digital input. And so on for the other 3 modules. These input/output addresses in the master and the slave are only data exchange areas, or mailboxes. You can copy data to and from these I/Q and PIW/PQW addresses in your program at any time, for your own purposes. Hope this helps, Daniel Chartier

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9/2/2010 3:13 PM	Rate (0)
Thomp_123 Posts: 11 Rating: (0)	As simple as that! Thanks Daniel, I think that was the final peace of the puzzle. Phil_123
Thomp_123 Posts: 11 Rating: (0)	Last edited by: Phil_123 at: 9/2/2010 3:25 PM Last edited by: Phil_123 at: 9/2/2010 3:19 PM
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