ESD file(s) usage

[Bogdan Scintee]

      Hello,

   First, I want to thank to all contributors to this library. A fantastic work! I am quite new on this and in general to the Ethernet/IP communication. I have used before some stack for reading the PLC tags, but that was not requiring any much understanding of the entire process.

My understanding is that for implicit messaging, the one should configure the Input/Output assemblies. In the PLC side, the tags that wants to be exchange are mapped to the corresponding assemblies on a particular position, like a memory mapping. And here are coming the questions:

1. The data type for the assembly can be one of the defined types (BOOL, SINT, DINT, etc.). This means that all members of the assembly must be of the same type, or we can have mixed types in it (i.e. 2 SINT, 4 REAL,...)?

2. Is there a mechanism in the existing library, letting to configure the application based on an ESD file? Here I am referring to the input/output assemblies with their members.

2. Is there already a way to extract from the received data each parameter of the assembly as defined in the ESD, or the user should write its own functions (no blame, just want to make sure that I am not reinventing the wheel).

Thank you in advance for your answers and best regards,

Bogdan.

[Martin Melik-Merkumians]

Hi Bogdan,

1. If you define your assembly as array of Bytes you can bast your desired basic data types easily into BYTE representation, and store it here. If you want to have an explicit array all types must be the same, as mandated by IEC 61131-3.

2. No, there is not

3. No, there is no mechanism for this, but if you implement may I ask you to share this as part of the project? :)

Best,

Martin