Currently I’m using MQTT to send pub/sub data from my master NoteCard, to a MQTT cloud server, then to my remote Notecard. This works but I was looking in the provided Accelerators at the Cellular Modbus Client. This accelerator does not mention going to a cloud server and describes going NoteCard to NoteCard using only NoteHub. We are currently using Modbus PLC’s and the firmware for the SWAN looks fairly simple.
Question is: Do the Cellular Modbus Clients need to go through a cloud server other than NoteHub? (Our PLC software compensates for failed communications) < OR> basically can one Notecard communicate directly to another NoteCard using NoteHub?
1 Like
Hi Don,
Thanks for your question!
This accelerator does not mention going to a cloud server and describes going NoteCard to NoteCard using only NoteHub.
Just so we’re on the same page, this accelerator app is only using one Notecard. The idea is that you send Modbus commands from Notehub via the requests.qi Notefile to that Notecard, the Notecard sends the command to a Modbus server, gets the response back, and puts the response in the responses.qo Notefile. When the Notecard next syncs with Notehub, those responses.qo Notes show up in the Notehub UI. In crude diagram form:
Notehub → Notecard (Modbus client) → Modbus server → Notecard → Notehub
If I understand your setup correctly, you have something like this:
Master Notecard → Notehub → MQTT cloud server → Remote Notecard (Modbus client) → Modbus server → Remote Notecard → Notehub → Back to your cloud server? I’m not exactly sure what the full return path is.
And you want to know if you can eliminate the MQTT cloud server from this architecture. Is that correct? Or have I missed something? I just want to make sure we’re on the same page before diving into solutions.
Thanks!
Hayden
Thanks for the info, I was just wondering why two noteCards can’t communicate with each other just through NoteHub if they both use Json.