S7 IO REDUNDANCY

[PIONEER]

Dear all, as I am doing a project that have one analog input and one analog output as redundant, so I must use io redundancy blocks in my project. I have looked to Simatic Manager samples and there is one sample for this application but it is not clear and i don't understand it. please, if any body knows how is this configuration, help me. thanks.

[Nil]

Dear Pioneer, What exactly u mean by one analog input & one analog output?? Is it the card or channel???? Use FB450 & FB451 for Redundancy Inputs & Outputs. U just need to call them. More over I think, u need to even call FC451(Redundancy Depassivation). This should be called in OB83 or OB85. Well I tried all these on PCS7 & never happen to take care of so many things, since PCS7 itself takes care of redundancy. Gud luck. Regards Nil

[PIONEER]

Dear Nil, thank you for your reply. I mean one channel analog input and one channel analog output. for this I used two analog input and two analog output cards.I have two ET200M racks and each rack has one AI and one AO card. How I must call FB450 & FB451? in which OB I must call this FBs? I programmed OB1 as main program cycle.

[Nil]

I mean one channel analog input and one channel analog output. for this I used two analog input and two analog output cards.I have two ET200M racks and each rack has one AI and one AO card. How I must call FB450 & FB451? in which OB I must call this FBs? I programmed OB1 as main program cycle. Hi Pioneer, Ur h/w config is ok. FB450 (Red_In) and FB451(Red_Out) should be called in the cyclic OB. U can call them in OB1. These normally don't have any inputs, but have outputs. The outputs for both these blocks are return values. Also remember to call FC451(Red_DEPA) in OB83 & OB85. I did this in PCS7 & it worked for me. But in PCS7, we need not call any of these blocks. Once redundant IOs are defined, the PCS7 itself creates all the necessary redundant blocks. Let me know, if you need more help. Regards Nil

[PIONEER]

hello Nil, thank you for your reply. it was very helpful,but as i attached my program screenshot, in one FB I get a redundant analog input and process it.(PT-304 as I described in image.) I know it is wrong because the other input (PT-304_2) has no role here! Exactly my question is this,how I must use FB 450 here? can I use RETURN VALUE OF FB450 instead of PT-304_1?if answer is yes, how I can do this? I will be pleasure if you give me a sample project if you have.(email : gh-zarei@tamameng.com) I took a look at S7 sample project, but it wasn't helpful! Thanks and best regards. Pioneer untitled.bmp

[Nil]

Hi Pioneer, Can u send me the screen shot of ur h/w. Is ur CPU, IM redundant?? which CPU r u using??? Regards Nil

[PIONEER]

Hi Nil, all hardware configuration is OK. my problem is in programming. also I send you some screen shots. regards.

[Nil]

Hi Pioneer, Had a quick look at the h/w. Its gud. Got a small suggestion ... Why don't u try AO redundancy. This will be bit easier, since in the case of AI redundancy we need to simulate 2 signals to be fed to both the modules. Define 2 AO modules as redundant. Then write some value (Say50%) to one of the module(Say channel 1 of 1st module). Then check the output current at both the modules 1st channel. U should get 6mA from the 1st channel of both redundant module. Let me know how this works...... Just add FB450 & FB451 in OB1. Just call each of them in 2 separate rungs. Gud luck. Regards Nil Edited July 1, 2009 by Nil

[PIONEER]

Hi Nil, thank you for your fast reply. OK, also I have one redundant output but I want to know how must I program inputs and then outputs. I couldn't understand, can I use RETURN VALUE OF FB450 instead of PT-304_1?(in picture FC 105 needs input, and input is PT-304 that is redundant,not PT-304_1.) I mean what I must use for FC105 input ? if answer is yes, how I can do this? best regards. Edited July 2, 2009 by PIONEER

[Nil]

Hi Pioneer, I am sorry for the delayed reply. Find attached S7400H manual. Check the Chapter 10 named "Using I/Os in S7-400H". U can go thru the page 134 & 135. Its very clear where the Redundant blocks are, and in which OBs these need to be inserted. U need not do anything with the return values of redundant blocks. These values can be used only for diagnostics in case of error in return code Hope the above is clear. Gud luck Cheers Nil S7_400_h_en_en_US.pdf Edited July 6, 2009 by Nil

[Nil]

Hi Pioneer, Well, I tested the application on of the H-CPu's & its working perfect. I was able to achieve AO redundancy. Refer the manual which I posted in my earlier post. (Pages 134 & 135). Read them very carefully. Feel free to ask me if u need further clarifications. I shall not be available for the next 3 days. Shall msg back to u once I am back. Gud Luck Cheers Nil

[PIONEER]

Hi Nil, thank you for your reply.I read the manual, it was very helpful. but unfortunately I don't know the result of FB 450 where be saved. in simatic manager help about FB 450 I read a text like this: "First the two values of the analog input channels are read and analyzed to see if they are within the allowed discrepancy window. If both values are within the discrepancy window, a uniform value that was set in the hardware configuration (min/max), is formed and written to the lower memory area of the process input image. Following this, the uniform value of the channel is saved in the appropriate DB." my question is which DB?how can I define this DB , or if it is pre-defined how can i reach this DB? I mean if I want to use the result of this two values,for example in HMI how could I reach to this value? what is lower memory area of the process input image how can I reach this value? I want to use this value in HMI. Thanks and best regards. Pioneer

[Nil]

Hi Pioneer, Sorry for the delayed reply. Find attached the reply for the same topic which u posted in siemens site. https://www.automation.siemens.com/WW/forum...p;PostID=127341 What H-H replied in the post is correct. Only the lower address can be used in the application. But anyway I am not sure what happens if the lower address module is removed and if you still happen to read the address of the removed module. Posted the same to H-H. Lets wait for his reply. Also in the h/w don't forget to specify the additional parameters for the AI redundancy. Regards Nil

[PIONEER]

HI NIL, thank you.

[Nil]

Hi Pioneer, Just check the response what user H-H replied on siemens site. U may use the same link which was last posted by me. Hope this helps. Regards Nil

[PIONEER]

http://www.automation.siemens.com/WW/forum...amp;Language=en

[Nil]

Hi Pioneer, Try using PIP instead of OB1 P1. Also donot forget to assign the PIP used to one of the cyclic OB's in the hardware configuration. Regards Nil

[PIONEER]

Hi Nil, thank for your answer. I tested OB1 PI and IW addresing in my program and it is working properly with analog input modules, 331-7KF02-0BA0, but with analog output cards it dosn't work and as i described at first it is working but when i remove first module and insert again then remove second module and insert again , it doesn't work. also I programmed OB 30,31,32,...,38 but OB 30 and 31 didn't downloaded to PLC, just OB32 downloaded. Another question, what is PIP? how it works? When we use PIP? thanks and regards, Pioneer. Edited July 24, 2009 by PIONEER