S7 MPI or Profibus?

Hi to all plc community,

I want to create a small project with 1 analog input (PIW 124) to a S7-300 and 1 digital output (Q 124.1). In this project, I want to transfer somehow this AI to a graphical object in protool. I also want to transfer another Real, or Integer value from protool to S7-300 as a set point (or limit value). Then on the PLC the AI and the limit value are compared and the comparison result sets or resets the Q124.1. All this should be played on Protool Runtime.

From this project I have allready done the AI move function, the scale function and the comparison, but nothing about the communication part.

Could you advise me on that? Which is the easiest and cheapest communication protocol to use? Consider that the distance between the PC and the PLC will be about 50-100m (150-300 feet).

I should also mention, that I haven't bought anything yet, neither the plc, nor the pc card. So if you can advise me on which modules to buy I would appreciate.

Is it possible to simulate all this with the PLCSim and the protool rt, without the forementioned hardware?

Thanks in advance

Hi


If your protool application is on a panel that supports MPI I would choose MPI comm.

This is the cheapest way to communicate with panels becaurse you can use a cheaper CPU, if you go for Profibus the Cpu´s are getting more expensive.

Hope this helps
Regards
Brian

Hi Brian,


thanks for your quick responce.

The protool application is on a regular PC with no additional peripherals for communication. I'm starting now the project and when I decide which protocol to use, I will buy the proper equipment.

My question is first if I can simulate with plcsim and protool rt the communication PC-PLC and how.

u need an mpi cp on the computer side cp5611 i guess

for simulation u can set the communcation on the rt to mpi address 2 , and run the plcsim it should work ( i tried it with wicc but for protool i am not sure)

Please note that u will need a runtime license to your protool project

is this a part of your project , or this is all the project ?
do u have to use s7-300 ? can u use 200 instead ?

can u use a op instead of a pc ? it will be much much cheaper

give me more details and i can help u for a suitable configuration


Best regards
Amr

Thanks Amr,

In the project I have to do this 8 times, for 8AI from 8 sensors. I don't think its a big deal, what is unknown for me is the communications part.

As for the S7, I would prefer the 300 series. As for the PC it allready exists. The only thinh I should buy is the CP module.

Hi Vit-A-Jim.

Yes, you need a CP5611 card.
And you need a runtime license for the Protool application on the PC.

The MPI port on most S7-300 CPU's are non-isolated.
Siemens states that the maximum distance is 50 meters with these non-isolated ports. However, it may be an overstatement, try to see if it works (I think it will) at 100 meters.
If you run into problems, you may have to add an RS485 repeater to extend the reach of the MPI network.

Not sure if what you describe is one project with 8 analog inputs, 8 projects with 1 analog input each, or 8 PLCs connected to 1 Protool PC.
Try to explain exactly what you want to do.

I forgot:

Is it possible to simulate all this with the PLCSim and the protool rt, without the forementioned hardware?

Click to expand...

Yes. Protool RT can connect to S7-PLCSIM.

By the way, I think that if you could draw a picture of the layout of the application, including the disatnce between each component, then I can help you better.

Please note the following : The price of the cp+license 128 tag is about 1200 Euro.(+ pc price)
u can buy an op starting from 300 Euro.
Also note that u need protol pro and not protol , if u have protol u will need to upgrade yr engineering software to protool pro


Best regards
Amr

if u decide to use s7-200 u can have also software called pc access , this is an opc server that enables u to connect the s7-200 to excel, visual basic,... where u can monitor your data without the need to expansive runtime software

Thanks a lot.

What I have is a single project with 8AI and 8DO. I measure 8 AI and if they overlap some setpoints, I set some DO's or reset them. I have already done some work with the protool andnow I'm in the status of deciding which equipment should I use.

Amr, do you have any info about those OPs? Do they include everything I need? in which operating system do they work? are windows based?

Thanks.

any op will do what u want for example op7 , this is a text based
u can check what u can make with it by creating a project with protool
for windows based u can have op 270 but this is not that cheap but u can buit your visualzation ,same as scada
there are the new op but they use wincc flexible not protool
such as op 73b for example
check siemens site for different op's

Finally, I decided to use a PC.


As for the connection, I found two mpi cables with great difference in price. These are:
1) 6ES79720CB200XA0 - SIMATIC S7, PC ADAPTER USB F. CONNECTION OF S7-200/300/400 C7; WITH USB-CABLE (5M) CAN BE USED UNDER WIN 2000/XP - 315 Euro !!!!

2) 6ES79010BF000AA0 - SIMATIC S7, MPI CABLE FOR CONNECTING SIMATIC S7 AND PG VIA MPI 5M - 28,95 Euro

- Can I use one of these for the connection of PLC and PC with protool rt?
- Do I need any special equipment (like PCI card) on the pc side?

- Can I make myself a longer cable to extend up to 100m?

1 is a USB adapter to connect a PC to MPI
2 is a 5 meter cable
You will need this, or some adapter, to program the PLC and/or HMI.

OP stands for Operator Panels also called an HMI (human machine interface). This is the Siemens site for their HMI's; http://www.automation.siemens.com/simatic/compact_info/html_76/simatic-hmi.htm
The panel would eliminate the need for a PC and may be a less expensive option.

Hi vit-a-Jim.

For 100 meters I do not recommend the USB adapter.
The USB adapter must hang directly off the MPI programming port on the PLC (because it draws 24V from the port). You can extend it through a number of steps, but forget it.
A CP5611 is a PCI card with a genuine MPI/Profibus port.
It only costs 50% more than the USB adapter.
There may be a potential problem with the reach of MPI port on the S7-300. However, I think it should work even at 100m. If not, the solution is to intall a repeater.