485 direction signal

Is there a way for XBee module to generate direction signal for RS485 transmission? I’d like to have stand-alone master module with XBee and without other components (except from RS485 driver) and connect it to RS485 slave device.

By “485 direction signal” do you mean RTS/CTS? If so, these are controlled by the configuration of D6 (RTS) and D7 (CTS). D7 has a 485 Enable Low or High option.

RS485 don’t have RTC/CTS signal. There is a need to indicate if device is reading or writing. I tried to use D7 but it don’t work. IT changes state after transmission start but remains in this state even when transmission ends.


For the RS485 to function, you need to set the D7 parameter on the radio. Then you need to connect the radio to an RS485 chip. Or you can connect your RS485 device to a Digi RS485 XBee adapter.

I’ve tried it already but I don’t work. I set D7 = 7. After XBee power up CTS is low, good. After receiving transmission it goes high, good. But it remains high. I need signal that goes high after starting transmission and going low after transmission ends.

What firmware version are you using? Do you have the CTS pin connected to the TX enable line of a 485 chip?

I’ve got 0x2241 firmware and yes I’ve connected TX enable pin with CTS pin. Is it a kind of bug? It worked for a while but once again it’s the same. After first transmission from Xbee to MAX485 CTS goes high and stays high so Xbee can’t receive anything from MAX485.

Any ideas? Maybe setting D7 = 7 is not enough?

I’ve found something strange. The the first received transmission after device reset is 0xAF 0x3F 0x21 0x8D 0x0A then in rs485 mode (DIO7 = 7) CTS pin is stucked high and receiving via rs485 is impossible. In other cases everything works fine (CTS goes low after transmission). Even this set of characters works fine when is not sent as the first packet after xbee reset.