Differences between OPC and S7A
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Question: I need to communicate with the S7-300 using IFIX. Previously I used OPC for this purpose, but now the manufacturer has recommended using S7A for communication. What is the difference between OPC and S7A? Thank you!
A little information: S_7: Supports three ways of connecting to Siemens S7 series PLCs, namely: Profibus (L2), Industrial Ethernet (H1), and Standard Ethernet (TCP/IP). These three connection methods are described as follows: Profibus: Supports FMS and MPI protocols. Required PC hardware: CP 5412-A2 PC Board for PROFIBUS. Required Siemens software: S7-5412/Windows NT version 1.10 or higher. Communication modules for the PLC: CP-343-5, CP-443-5 EXT; these can be connected directly to the PLC’s MPI communication port. Industrial Ethernet (H1): Required PC hardware: CP 1413 PC Board for Ethernet. Required Siemens software: S7-1413/Windows NT version 1.10 or higher. Standard Ethernet (TCP/IP): Required PC hardware: 3-COM Etherlink III Card – Ethernet. Required Siemens software: SOFTNET S7 for Industrial Ethernet / Windows NT. Other Siemens software for diagnosing and configuring S7 PLCs: PG/PC Interface Software Configuration Release 4.0.7.4,153; STEP 7 Software version V 3.02 or higher.
Is there any information available on S7A for IFix? Thanks!
I’m not quite sure about the S7A communication method used in IFIX; I guess it might be similar to the communication method used with Siemens’ S7 systems. If that’s the case, it would be more reliable than the OPC method.
SA7 is an interface software specifically designed to support communication between IFIX and Siemens S7 PLCs, while OPC is a universal interface software that enables communication between various PLCs, HMIs, and third-party devices. In other words, OPC exists to address the issue of inconsistent communication protocols among different manufacturers. Almost all industrial control products I’m aware of support OPC, whereas SA7 can only be used for communication between IFIX and S7 PLCs. OPC is an international standard. I suggest you find some information on OPC to look at.
S7A is a third-party driver developed by a German company; it is a paid driver that offers a 2-hour demonstration. Unfortunately, every time I try to obtain access to it, it proves to be more convenient for creating point lists compared to the Simatic Net software, and it’s easy to use