Read data from S7-300 to S7-1200

Hi,

I read an interesting forum thread below. I want to read data from S7-300 to an S7-1200 , what is the best move? Today I use a ACCON-NetLink-PRO compact for this purpose. What I would like to do is establish a connection where I can read specific adresses from S7-300. Would this be possible? On the gateways web-interface I can read as long as I know the adresses, so theoretically it should work to read it this way as well. 

My thought is to use the S7-1200 through a switch and read the data. Then reconvert it and send it to the cloud. So what I want to figure out, is it straight forward to read specific adresses? 

After looking on videos regarding Open user communication, this seems to be end-end communication and I only want to read data from the S7-300. And I can't rewrite the software on it. 

Basically, I have adresses to tags I want to read. Whats the easiest way? Observing values is possible through the http page of the device.

Is it possible to read 

https://support.industry.siemens.com/forum/se/en/posts/read-tcp-ip-packets-from-third-party-ethernet-device/83687

Take a look at How do you configure and program an S7 connection and the “PUT” and “GET” instructions for data transfer between two S7 CPUs? 

I am not a huge fan of the GET/PUT mechanism because it predates modern security practices, so enabling this capability in the S7-1200 opens a security vulnerability.  However, it does work, is supported in both S7-300 and S7-1200 PLC's, and you can take other security measures to protect your S7-1200 from attackers.

First of all, thanks for the answers from both of you ! :)

mmckayRet

Take a look atHow do you configure and program an S7 connection and the “PUT” and “GET” instructions for data transfer between two S7 CPUs?

I am not a huge fan of the GET/PUT mechanism because it predates modern security practices, so enabling this capability in the S7-1200 opens a security vulnerability.  However, it does work, is supported in both S7-300 and S7-1200 PLC's, and you can take other security measures to protect your S7-1200 from attackers.

 The issue with enabling GET/PUT mechanism is more that we have said internally that we do not want to touch the S7-300 long as we can. We use GET/PUT on newer machines, but as your saying... There are possibilities to make other security measures. 

The reason for this is that if those machine had a "quick fix" in the past, we dont want to risk downloading new software that doesn't have that "quick fix" aswel.

Duris_I

Hello,

I think use of PUT/GET will be not easy as expected here in posts. Reason? S7 PUT/GET expect some specific interface with available protocol capable so most important question is, to which interface on S7-300 you put ACCON adapter. Due adapter type is clear that only to MPI or Profibus but all depends also to S7-300 type CPU because in case of only MPI capable, you have only this choice and S7 PUT/GET will be not available. You can see now that many specific options you need take to account and CPU comm capabilities problematic is required as mandatory. I recommend to this situation also check CPU-CPU communication between S7 controllers documentation what can help you to understand more about this problematic.

 What I would like to use is the MPI interface. Today I read these value to Kepware with Siemens TCP/IP ethernet driver.

Thank  you for sharing the CPU-CPU communication documentation. But I am a bit curious, what do they use between S7-1200 and S7-300. I mean, one have an MPI/DP port and the other have Ethernet. This was one of my biggest issues, can it be the communication module from Siemens? 

The way I interpret this, there might be a possibility to load/transfer to the PN. I guess this violates my "not touching S7-300" right?  Do we have another CPU that can fit for this task ? :)

The S7-300 is fixed, but the S7-1200 is not. The reason why I want to add S7-1200 is that I want to be able to "rewrite" logic on the S7-300 to send out to the cloud. And if I'm going in to the S7-300, it would've been possible to do the logic there instead and not bother with the extra hardware.

Maybe my best solution is to use some Kepware feature to implenet the logic with higer level programming, the reason why I would like to avoid this is that in the company the higher level porgramming never really pans out due to that the skill doesn't exist in this. But maybe this is my only way out?

https://cache.industry.siemens.com/dl/files/908/78028908/att_1134019/v1/78028908_SIMATIC_Comm_DOKU_v23_e.pdf

Duris_I

Hello,

1. What I would like to use is the MPI interface.

Yes I know and therefore I answered to you that this isn't possible with S7-1200. There are some Gateways on market but I've never used them, simply waste time with MPI in this case is clear and not expected.

2. But I am a bit curious, what do they use between S7-1200 and S7-300. I mean, one have an MPI/DP port and the other have Ethernet.

This is what needs to be solved and discussed earlier in prj preparation. In S7-300 is PB DP or PN expected in case of use S7 comm with S7-1200 where similar interface you need have also. That CPU-CPU document show that very clear. Take f.ex. Profibus part and check S7-300 with S7-1200 what possibilities you have there in this case but you need take to account very clearly who is Client and Server in this case. With PN same, some CP modules are exists and can be used here, no doubts.

3. The way I interpret this, there might be a possibility to load/transfer to the PN. I guess this violates my "not touching S7-300" right?

Yes.

4. Do we have another CPU that can fit for this task ? :)

As CPU-CPU document shows and what I recommended to you check few lines higher.

5. The S7-300 is fixed, but the S7-1200 is not. The reason why I want to add S7-1200 is that I want to be able to "rewrite" logic on the S7-300 to send out to the cloud. And if I'm going in to the S7-300, it would've been possible to do the logic there instead and not bother with the extra hardware.

Your choice...

6. Maybe my best solution is to use some Kepware feature to implenet the logic with higer level programming, the reason why I would like to avoid this is that in the company the higher level porgramming never really pans out due to that the skill doesn't exist in this. But maybe this is my only way out?

Never used OPC in my history but it looks to me as best option in my opinion if you don't want step to more complicated cfg about PB or PN modules and re-configuration and re-program all things and sides.

 Thank for the elaborated answer.

1. I did not understand the first time. Thanks for clearing that out. :)

2. The reason for this is simply that the S7-1200 comes pretty cheap and applying logic on it is straight forward. But after what I am reading, this seems not to be possible.

4. If I understand this correctly, the put/get doesn't work. Reading the MPI network wont work. I'm not following what your recommendation is ? :) 

5. I think I dont have another option, I think im missing what is possible? :)

6. I think so too, I think this might be the best solution for me, to run with OPC... Will se what I will do. 

Duris_I

Hello, 

2. it is possible but with change of HW cfg and program required things on both sides. As I've described, PB and PN modules are available or some MPI gateways (you have ACCON already) can be used to MPI connection but all also depends about data amount you want exchange, with MPI you can't expect big effect.

4. PUT/GET will work only if you'll do HW changes as I said with PB or PN.

5. It looks to me you still don't understand to problematic I've described. All is inside CPU-CPU document so take a look to this with careful learning.

6. yes, if your OPC can connect to that S7-300 via MPI then no problem. On other side your posts still missing your S7-300 HW what exactly type it is, if it also include DP port because this can be solution also.

 Sorry for the slow answer. 

2. We are talking about roughly 200-300 tags maybe. That should be managable from the MPI Network. The only thing laying 

4. I actually got this to work today... Tried it last week and it didn't work. But now I have a solution on this.

5. Your correct, I tried reading the CPU-CPU and understanding it... I feel a bit silly when reading it and not really understanding. As I understood it, I shouldn't be able to read with PUT/GET at all. But indeed I do?

6. Sorry about missing that. Cpu is 313C... The thing is, this is not a fixed CPU. In this case, it will be 313C. The only fixed thing is the MPI. They will have DP ports aswell, but to do something there I believe I need to add a "slave" on the buss right? 

Never the less. This is now solved and I really, really appreciate the information and lessons ! :)

The get did not work since I had the wrong ID somehow and didnt know how to work with pointers in Tia. Now to the next achievement and thanks once again !

Duris_I

Hello,

eeeeeehm very sry, your last post is really not clear to me, absolutelly sry. It has simply informations that are mixed with expectations that are not same as you've declared before you want to do. Really also info that all is working now is also strange because no info I see where you did that cfg changes. With 313C you say that they will have DP ports but who and what this means with more ports? Generally, if I have some CPU where other interfaces are available (PN or PB) this is expected to be included with type as 313C DP or 313C PN/DP or only 313C what means only MPI. Simply my intention with help here is still in case that S7-300 side can't be changed with cfg but your post simply shows something else and therefore not clear to me. I don't know if my help is expecetd further here because all possibilities as I see them with your described cfg, I said already in first posts.

 Hi,

Sorry for being unclear then. First of, my problem starts with multiple machines. I dont only have a 313C with DP ports, some have the communication module and so on. 

I haven't really touched the s7-300 PLC at all while configuring. The only thing I did was add the MPI Gateway on the available MPI Port. But yes, most of them have DP port next to it. (atleast what I have seen).

The goal was to read data from a S7-300 cpu with an MPI port. This was accomplished with rhe adapter I have shared above. The configuration was done on the adapter. And through that adapter i could retrieve data with a get method. 

I think you have helped me more than you think, and i appreciate it ! :) I hope I cleared up the questions you may have?