On time

Is there a way to change the amount of time an XBee end device is active when waking from periodic sleep with no RF signal present?
I want to be able to periodically check for a nearby device as efficiently as possible. IE more frequent checks with minimal time on.

On the XBee-PRO 900 Digi Mesh code, there is not a function for an End device to wake and check for data and if there is no data, to go to sleep.

rbrtwtrs - what firmware are you running?

I suspect what you mean to ask is, if the node wakes and finds no ‘neighbor’, to treat that as a normal situation and to go back to sleep ASAP, instead of scanning all channels for a neighbor?

I’m running XBP09-DP 1061

Yes I need it to go back to sleep ASAP if no neighbor present. If there is a radio present I want to switch to a mode where it stays active for an extended period. Idea is to minimize lag time in passing messages once a connection is established.
As I currently have it configured I have an SP of 5 secs and an ST of 30 secs. This works but the radio stays on for ~.5 sec every wake period. Would like to reduce that time if possible.
The application has a master command console allowing a user to send operating commands via a menu or query the end devices for data.

I have a uC on the end device with I/O control of the sleep and CTS pins and a UART connection to the XBee. I have a PC serial connection to the coordinator.

I don’t know the answer, but that might also relate to how the XBP09-DP does frequency hopping.

When your device wakes, it literally needs to wait long enough for the ‘system’ to cycle around to a specific frequency because probably is high that when it wakes, the ‘system’ is off on a different frequency than your XBee woke up listening too. Therefore, the XBee cannot just say “Oh, no one’s here - go back to sleep” because they may be here soon but not quite yet.

So it is inherent in the way the modules operate? The only possible way around it being to limit the operating chans so that it doesn’t have to cycle thru all chans?
The system is used in remote locations with little chance for interference so I could probably get away with specifying a specific operating chan if necessary.
Would that work?

I’m not sure you can limit the channels.

Under Zigbee and DigiMesh 2.4, which do NOT hop but sit on 1 channel, you can say to only use 1 channel.

My understanding of the 900 product which hop is you have a ‘fake’ channel setting which deson’t limit the channels, but just defines which of “N” hopping patterns to use.

You may have to instead make your wake-delay dynamic. So if the unit wakes and does not find a network (or maybe after 3 times), then sleep 10 times longer between waking. I can’t think of any other way to reduce battery life when the sesnor is ‘alone’.