Siemens S7-300 to S7-300 data transfer

[JesperMP]

If you are going to use the BSEND/BRCV method, then do not use the SFBs !
The SFBs only work with S7-400.
In stead use the similarly named blocks from the "CP 300" folder in the SIMATIC_NET_CP library.

 

[smakdown61]

If you are going to use the BSEND/BRCV method, then do not use the SFBs !
The SFBs only work with S7-400.
In stead use the similarly named blocks from the "CP 300" folder in the SIMATIC_NET_CP library.

Thanks! I think I've almost got this nailed down, but going back to my last question it look like it wants an attribute data block? What is supposed to be in that data block?

 

[JesperMP]

You must be referring to the instance data block that must be assigned to every FB or SFB.
You just give it any free DB number. STEP7 will detect that the DB does not exist, and ask to generate it automatically. To this you just answer yes.

 

[smakdown61]

Ok, I think i've got it set up using the 342's, but I want to have a backup plan in case I can't get it to work using those. I also have the DP/DP coupler that will sit between the two cpu master DP networks. I already added the coupler to each network in Netpro, now I'm trying to figure out how to make an S7 connection between the two cpu's over the coupler? It keeps defaulting to the separate 342 network.

EDIT: It looks like I don't need to setup a connection parter. I just assign the input and output addresses of the coupler and move my data to those addresses right?

 

[KalleOlsen]

Yes. The coupler is a slave on both DP-networks. Be aware how you set up the in-out areas. Must be opposite on both cpus, it means PLCA: OUT -> PLCB: IN (first line entry) and so on.
Kalle

 

[smakdown61]

Yes. The coupler is a slave on both DP-networks. Be aware how you set up the in-out areas. Must be opposite on both cpus, it means PLCA: OUT -> PLCB: IN (first line entry) and so on.
Kalle

Thanks! When setting up the addressing, it looks like it maxes out at 64 bytes. I have 70 bytes that I need to transfer. Is there a way to increase that?

 

[KalleOlsen]

Yes, just add a new line.
K

Note this:
Since you are transferring reals (4 bytes) you should do it in one of this ways:
1: Select the io area in the process image area (normally under byte 127/255 - selectable).
2: Use any area, but select consistency by total length. This means that you will have to use FB DP_READ and DP_WRITE to communicate. Be aware that you will need 2 calls of each since you have 2 lines in the area setup - (first call 64 bytes, second call 6 (or best 8) bytes.

Kalle