I need to output a minimum 1Khz pulse train out of a digital pin on a remote Xbee using API mode. The coordinator is being driven by an Arduino using serial API commands. My first attempt showed a very slow maximum reliable switching rate of only 2Hz. Any faster input rate resulted in unreliable oputputs until I got up to 200Hz, which resulted in absolutely no output.
So the question is- What is the maximum line passing switching rate using API?
Are you sending data to default broadcast address (0xFFFF)?
If so, try unicast by providing destination MAC address. It should improve current situation.
The 900 HP module like any Mesh based product is only going to be able to have a max throughput of about 60bps. (Check the throughput section of the manual for actual rate) . This is not going to give you a rate much above the 2Hz rate you are seeing. If you need higher date rates then I would suggest looking at the XBee 802.15.4 modules or using external processors that can perform the action with minimal data transfers.
Thanks mvut. I also have the Xbee Pro 802.15.4, which I tried before the 900HP. The Pro 802.15.4 specifically states it doesn’t like updates faster than every 20ms. The 900HP says it is happy with updates every 1ms. I wasn’t able to replicate that, probably due to my lack of understanding of all of the API parameters. I have gone back to the Pro 802.15.4 and now I am using ADC inputs and PWM outputs, which easily exceed my speed requirements. I still have problems with my motor control, but since I am no longer trying to directly pass the pulses through Xbee the slow update speed is no longer and issue.