Hi Djools,
If I execute your command and look in the Debug Logger it says:
* "Parameters must be enclosed in '()'!" for "TcpSend" at 1/1 [Severe/Parsing]
For me, it looks like you added the part with CR wrongly as it is not inside the round brackets. Maybe there is also a missunderstanding about the TCP-connection ID in addition to the first issue. In the Connection Manager, is the ID for the TCP also 5? As I just made one connection, it has ID 1. So if I want to send a text (e.g. just letter x) to the recipient of this connection it would be:
Tcpsend(1,'x')
So if I select x and copy the example from liamohanlon including line feeds and many spaces it is (for Barco ID 5):
Tcpsend(1,'{[LF]"jsonrpc": "2.0", "method": "property.set", "params": { "property": "optics.shutter.target", "value": "Closed" }, "id": 5[LF]} [LF]')
If I take Sam's example without line feeds and spaces, I get:
Tcpsend(1,'{"jsonrpc":"2.0","method":"property.set","params":{"property":"optics.shutter.target","value":"Closed"},"id":5}')
Let me know, whether that worked for you