Hilscher Forum
NPIX-RS485 with auto direction control now available - Printable Version

+- Hilscher Forum (https://forum.hilscher.com)
+-- Forum: netPI - Ruggedized Raspberry Pi with Industrial Ethernet (https://forum.hilscher.com/Forum-netPI-Ruggedized-Raspberry-Pi-with-Industrial-Ethernet)
+--- Forum: Hardware (https://forum.hilscher.com/Forum-Hardware)
+--- Thread: NPIX-RS485 with auto direction control now available (/Thread-NPIX-RS485-with-auto-direction-control-now-available)

NPIX-RS485 with auto direction control now available - Armin@netPI - August-26th-2019

We changed the RS-485 transceiver used on module NIOT-E-NPIX-RS485 in REV#2.

The new part - MAX13488E - features auto direction control and is switching between TX (transmit) and RX (receive) mode automatically once you enabled it. The advantage is to be no longer compelled to handle switching in software causing unpredictable/prolonged switching times and loss of serial receive data if too long.

The MAX13488E is pin compatible to the previous used transceiver SN65ALS176 in #REV1. Instead of using the TX_EN pin to switch between TX/RX as done before on #REV1 you have now just to set the TX_EN pin to "high" state a single time and automatic direction control is enabled.

With Node-RED for example you could just inject a "true" to a rpi gpio node directed to GPIO17 (TX_EN) and you are done:

[{"id":"287692d1.c61e06","type":"inject","z":"d31910c1.fd0618","name":"","topic":"","payload":"true","payloadType":"bool","repeat":"","crontab":"","once":false,"onceDelay":0.1,"x":295.5,"y":599,"wires":[["6bbb3ed9.4bb6d8"]]},{"id":"6bbb3ed9.4bb6d8","type":"rpi-gpio out","z":"d31910c1.fd0618","name":"","pin":"11","set":"","level":"0","freq":"","out":"out","x":483.5,"y":599,"wires":[]}]

After pulling the TX_EN pin to high state the NPIX-RS485 module will get compatible with any serial communicating program or Node-RED node.

Download the latest NPIX modules documentation highlighting the modules' difference in the download section here .