Mpi Interface

[ravilal]

How Can I Get Data Of One Plc To Another Using Mpi Interface?please

Reply

 

[jvdcande]

If you're talking about using MPI to transfer data between S7-300/400 PLCs then you can use SFC67 - XGET or SFC68 - XPUT. These functions can be found in Libraries - Standard Library - System Function Blocks. To get more info on them, select them in 'Program elements' and press F1.

Beware: it can not be done with some older CPUs. I have some S7-314s with MLFB 6ES7314-1AE01 and these don't have these functions on board. My slightly newer, but still reasonably old 6ES7314-1AE01s however can use this method.

Kind regards,

 

[gregoryg]

You can also use SFC65 (X_SEND) and SFC66 (X_RCV) for sending and receiving data. This requires programming from both sides (sender and receiver).
If one of communication partners is S7-400 then you can configure S7 connection from S7-400 side and use PUT/GET functions (S7-300 acts as data server).
For two S7-400's connection can be configured in both stations and you're able to use all functions designed for configured connections.

 

[rajsiyer]

Hi ravi;;


Seems a Hindi can help a Paki(HEH HEH! )

MPI network using Simatic Manager is the easiest. You've to setup a G-DATA table. On Simatic Manager, Open the dialog box (This when the cursor is on the MPI icon) and follow instructions. If you don't have the MPI cable, its very easily made. It is 1_1, 2-2, 3-3...9-9 parallel cable.

So setup the G-Data System and thePlcs exchange data each scan cycle.

 

[jvdcande]

If you don't have the MPI cable, its very easily made. It is 1_1, 2-2, 3-3...9-9 parallel cable.

MPI only needs two data signals (A - pin 8 and B - pin 3) and the cable shield (metal housing of the connectors), together thats three wires. You mention a fully used 9 wire cable. The communication is also not parallel, but serial over RS485 (hence the A and B signals). You can find more info here by searching for 'MPI' and 'pinout'.

The fully wired cable might (not shall, you can be lucky) damage the PLC, because you are directly connecting the powersupply levels of the two PLCs. If those levels are not equal, then you can get really big currents in the cable.

Kind regards,

 

[rajsiyer]

Thanks bud...


I've been blind to this all the time. Right you are of course considering that the MPI adapter itself draws power from the PLC's port.

 

[Werner]

Assuming youre using S7 plc's. You can define "Global data". Right click on the MPI network and select global data. Here you can define interfaces between multiple plc's. We use this in stead of potential free contacts between plcs. For global data to work the plc's must be in one S7 project.