I have a problem to establish a connection between controller S7-300 and S7-1200. Controller S7-300 consists of processor 6ES7 315-2AH14-0AB0 V3.3 and 6GK7 343-1GX30-0XE0 . And S7-1200 6ES7 214-1BG40-0XB0 V4.6. The communication is via Ethernet and they are connected directly through a switch. They are programmed with TIA Porta19 update 3 in one project. When S7-1200 reads from S7-300 with GET, data is received only once and then GET fails and does not finish work. Firmware of 300 is the latest and correctly described in the project. Besides GET/PUT, are there any other instructions I can use to transfer data?

Hi danailp,

to answer your question; Yes, there are other blocks you can use to transfer data. 

• BSEND/ BRCV is double sided and application acknowledged
• USEND/URCV is double sided and system acknowledged
• TSEND/TRCV is double sided and system acknowledged

In a double sided communication, both partners need to know about the desire to exchange data. 
In a system acknowledged communication, the firmware acknowledges the receipt of a data packet to the sender. The user program has no interaction until here.
In an application acknowledged scenario, the user program has to call the corresponding receiveblock (BRCV) to confirm the receipt of the data packet. The sender won't report “Ready” or “Done” until the receiver called the receiving block.

While PUT/ GET is only single sided and system acknowledged, the receiving or serving side (S7-300) does not interact with the user program to inform about changes. 

My recommendation is to use either BSEND or the TCP native communication with TSEND.

Hope that helps

It turns out that GET does not work with communication processors. I found that GET_S/PUT_S is available in S7-300 and with them I can make S7-300 active to handle the communication. TRCV_C/TSEND_C is not available for this processor but I will try with the other instructions.

Hello danailp

you can check your general options also here:

https://support.industry.siemens.com/cs/ww/en/view/78028908

Bye Murof