WIFI Communication between S7-300

Hello,

I need some help on my project. I use Simatic Manager with Step7. I have two PLC S7-300 (Master/Slave) with Profibus communication.

I bought two scalances (Acces Point W788 and Client W748), I put them in the Hardware Config with IP W788: 172.20.16.32 and IP W748: 172.20.16.13

I don't know how to configure this WIFI communication as redundant to my Profibus.

Do you have some tips or exemples?

Best regards.

Rikou

Hi,

which kind of CPU do you use?

I need little bit more informations.

Step7 version.

HW-Config.

Configuration of the scalances.

Best regards

methos

Both are CPU 315-2 PN/DP 

STEP7 V5.5 + SP2 + HF1

Master CPU Profinet: Scalance-W788-1-M12 | Ethernet: IP 172.16.20.32 / Mask 255.255.240.0

Slave CPU Profinet: Scalance-W748-1-M12 | Ethernet: IP 172.16.20.13 / Mask 255.255.240.0

I joined the Netpro view. 

Hello,

I do not know, if I understand you well:

Do you want PROFIBUS and WiFI at the same time? This would not work without redundancy protocols like MRP, RSTP etc.

Or instead of PROFIBUS, the Wireless communication?

For Wireless, you only must configure both SCALANCE W (SSID, Protection, IP) via webbased management. A NetPro configuration is not necessary.

The ip of PLC must be in the same network as SCALANCE W.

Hello Pittiplatsch,

Yes I have Profibus and I want to add WiFi for redundancy.

I want to send /recieve the same DB which I'm sending via Profibus between my two PLC, thanks too this WiFi.

I will have a look to the protocols, thank you.

Rikou

Hi Rikou,

please differ between

==> redundancy of physical Ethernet connection

==> software redundancy (Master-PLC <=> Reserve-PLC)

For redundany in network, you need a ring topology or SCALANCEs which supports meshed networks. And, all modules must  support special redundancy protocols.In this case, only one connection between the modules are active, the other(s) are disabled. If active connection is broken, a new connection is active.

With software redundancy, you have two PLCs, which synchronize each other. This can be with warm-standby (S7-300/ special blocks for software redundancy) or Hot-Standby (S7-400H)

 Hi,

Sorry if I didn't explain it very well, not easy for me in English

Pittiplatsch

For redundancy in network, you need a ring topology or SCALANCEs which supports meshed networks. And, all modules must  support special redundancy protocols.In this case, only one connection between the modules are active, the other(s) are disabled. If active connection is broken, a new connection is active.

 This is my case, if my profibus status is down then I will switch to WiFi.

Can I use simple BSEND & BRCV ? 

Hello Rikou,

MRP, RSTP etc. only works in Ethernet networks (MRP needs PROFINET).I do not know (and think) that you can combine PROFIBUS and Ethernet for redundancy in network.

Hello Rikou,

You can make the two types of connections that you want: 1 Profibus and 1 Ethernet (over Wireless).
You can not have Step7 make an automatic redundand switch between the two connections.
You will need to make the logic in the program (software redundancy).
For example if you prefer communication over Profibus, then you program it so that the cpu tries to establish the Profibus connection and if this succeeds, then you start communicating via Profibus.
If the communication suddenly fails, then you terminate the connection and tries to establish the connection over wireless.
If this succeeds, then you start communicating via ethernet.
You can then retry the Profibus connection for example with an interval of 30 seconds and when you succeed, you stop and terminate the ethernet connection and start the Profibus communication again.

See:
https://support.industry.siemens.com/cs/ww/en/view/18516182
for BSEND example.

I hope this helps.