Greetings. I have this weigh indicator transmitting data to a Raspberry Pi via RS232, specifically:
and being received by the standard Node-RED serial in node. It works fine, but for reasons that are unclear to me, after 2 or 12 or 18 hours or some other time period, the serial port stops receiving data. It starts reflowing again once I restart Node-RED or redeploy the flow. I have done a lot of reading on this and believe it may be due to flow control. You can see from the above that the Rice Lake unit is ONLY transmitting data, i.e. there is no 2-way communication that is usually in place with RS232.
The Rice Lake unit also supports RS485, which I am comfortable setting up and working with in Node-RED. However, before I go there, I wanted to ask a general question about RS485. Can RS485 be configured to always flow into the Pi, or if it can only be received by polling the device (i.e. using the Modbus getter node to poll every n seconds)? For my particular application, polling once per second would be too slow. I need closer to 25ms or so. Does anyone see a problem with that? For receiving weights from a scale, is there any advantage or disadvantage of RS485 vs RS232 that I may not be aware of?