Demo |
The Demo3D.PLC.Comms namespaces provides PLC (and other server) connectivity.
Namespaces| Namespace | Description |
|---|---|
| Demo3D.PLC.Comms | The Demo3D.PLC.Comms namespace provides a set of built-in Demo3D communication protocols. |
| Demo3D.PLC.Comms.AttrDb | |
| Demo3D.PLC.Comms.Builtin | The Demo3D.PLC.Comms.Builtin namespace provides default and example protocol implementations. |
| Demo3D.PLC.Comms.CIP | |
| Demo3D.PLC.Comms.CIP.AttrDb | |
| Demo3D.PLC.Comms.CIP.Nodes | |
| Demo3D.PLC.Comms.CIP.Nodes.Motion | |
| Demo3D.PLC.Comms.CPF | |
| Demo3D.PLC.Comms.Memory | The Demo3D.PLC.Comms.Memory namespace provides features to access PLCs which expose a memory-based protocol or API. |
| Demo3D.PLC.Comms.Tag | The Demo3D.PLC.Comms.Tag namespace provides features to access PLCs which expose a tag-based protocol or API. |
RemarksPLC connectivity is broadly split into two types.
- Tag
- Tag-based servers expose PLC data points as explicit tags. They tend first to expose their symbol table detailing all the tags that the client can access, and then offer some API or protocol for the client to access tags. Examples include EtherNet/IP CIP Class 3, OPC (UA and DA), and BR Automation PVI.
- Memory
- Memory-based servers expose raw PLC memory, allowing the client (Demo3D) to read and write bytes of data direct to/from the memory in the PLC. Examples include Modbus, Siemens S7 Functions, and Beckhoff TwinCAT ADS. These servers may also expose a symbol table, the symbols in the table are just a mapping from symbol name to memory address, and the underlying access is still direct to memory in the PLC.