I have search in the forum and I think that S7-200 cannot be a PROFIBUS master. However my tutor gave me this project: communicate between S7-200 and MM440 using PROFIBUS protocol. Is there anyway to work out this? And if it is possible, I hope someone can instruct me in detail, because I'm new to this and I don't know how to set up the connection and also the program for it. Thank you so much

Hello,

the EM is a slave module. You need a master. Can you use for example a S7-300 series CPU with Profibus?

And check the manual of the converter (GSD-file) for Profibus-setup.

Regards

Hello,

Yes, you are right. The master (S7-300) will send Control Word and Speed to MM440.

And you will receive Status Word and Actual Speed.

The S7-200 can only be a Profibus Slave, when you use EM277. It is not needed in this setting.

(Perhaps the S7-200 will generate the speed, you will have to transfer it to S7-300 and from there to MM440)

Best regards,

Wizard

Hello Melhk;

I believe Henri is on the right track, using the USS library you can setup the S7-200 PLC as a master to the MM4 drive; there would be no need for a Profibus-DP master (such as a S7-300) in your project, although Profibus cable and connecters are the recommended links to the drives. Check the requirements for your project and see if USS could be an acceptable solution to control a MM4 drive.

Have a look at these documents:

MICROMASTER (MM4), SINAMICS G120 (CU2x0x): Guidelines for reliable USS communication from PLC to an inverter

https://support.industry.siemens.com/cs/ww/en/view/12462284

USS instructions in STEP 7-Micro/WIN32 with MM4 drives

https://support.industry.siemens.com/cs/ww/en/view/6042107

Micro Automation: Simple networking and cascading of drives (MAS 26)

https://support.industry.siemens.com/cs/ww/en/view/21690362

And study the attached pdf, it is an extract of the S7-200 System manual describing USS communications (Chapter #11).

Hope this helps,

Daniel Chartier

hi Meihk,

Profibus-plugs are for 2 cables

So you can start with the CPU, then go to one slave and from that slave to the other slave. On the first and the last slave you have to put on the restistor.

SIMATIC NET PROFIBUS Network Manual System Manual

Slaves don´t have a program, they just have inputs and/or outputs, which are acting as an interface to controll the slave.

hope this helps,

regards,

1. Thank you for the solution. But is there another way? Because i'm just working on an assignment so I cannot afford like 30$ for a plug. Actually I'm using a normal 2 core cable instead of PROFIBUS cable and also DB9 port instead of PROFIBUS plug. I know it will be problem with noise or sth like that but the project is too small and the distance is around 50 centimeters. It's too hard to buy some industrial device in that tiny amount.

2. Do you mean I have to write program for S7-300, then moving control word to S7-200 input, and then move these control word from S7-200 output to MM440? But if so I still have to write some program like "move word from input to output" for the S7-200, right?

Hello Meihk;

I can only suggest that you follow the example program step by step, from top to bottom. Trust me (and Siemens programmers) it works very well. This is a very standard application.

For this program it has been decided that the S7-300 would read 2 bytes from the S7-200 and write 2 bytes to the S7-200 V-memory area. This is the simplest possible configuration for the data exchange, for your real program you will have to decide how many S7-300 output addresses will be sent to the S7-200, and how many V output registers will be read by the S7-300. Note that once the decision has been made to exchage 2 bytes in/2 bytes out between the 2 CPUs, a Profibus data module of size 2 bytes in/ 2 bytes out must be added in the S7-300 configuration of the Em 277.

Go ahead, one step at a time, and show us what you have configured when a step blocks you.

Hope this helps,

Daniel Chartier 

Hi dchartier,

It was my fault not reading that step. So now I think it's ok for me to work out the connection

However I'm trying to config the connection using TIA portal but I cannot find the similar tab to this. So is this possible to do with TIA portal or I have to use Step 7? 

Thank you