XBee To rs485 flow control

XBee & XBee Gateway XBee - Zigbee
1

I’ve got an XBee to RS485 adapter communicating to a ConnectPort gateway using Python.

I can send data from the gateway to adapter using the loopback Cluster ID 0x12.

I can also send from my RS485 device to the gateway.

But so far I’ve been unable to send from the gateway to the RS485 device.

I’m sure it has something do do with flow control, but I haven’t had any luck finding documentation on how to implement flow control from python. I did find docs on configuring the D7 setting:

http://www.digi.com/wiki/developer/index.php/Setting_Serial_Adapter_Baud_Rate

Any ideas on how to implement flow control for XBee to two wire RS485?

2

I presume you are using an exteral RS485 chip with the XBee. RS485 chips need to have the RE/DE pins ‘set’ when they have to transmit data over RS485.

By configuring D7=7 (RS485 Enable High) in the XBee DigiMesh firmare this will make XBee Pin 12 (DIO7) into a “transmit enable” pin. Just connect it to the RE/DE pins on your RS485 chip.

If by “flow control” you mean making sure 2 RS485 devices dont transmit at the same time then this must be done in your software.

Not sure this is helpful to you… just my 2c worth.
j