Hey there,
I’m wondering if the XBEE ZNET/ZB modules have something equivalent to the function of the Tn timer for the end device to monitor communication to the router/coordinator?
I was psyched about using these modules because of the I/O, thinking that I wouldn’t need a microcontroller. But without the failsafe, using the digital output is pretty risky.
Am I missing something?
Thanks for the help.
DB
where’s the data from the XBee sent to/from? Can that computer supervise connectivity?
stevech,
The xbee coordinator is connected serially to my computer through an xbee explorer running a simple serial application sending and receiving api frames. The xbee end device is stand alone with its i/o set up as DOs connected to leds for testing.
I noticed that if the application shut down, the outputs stayed in their current state, not defaulting to ‘off’.
I’m planning on using the outputs to drive solenoids. I’m worried that there’s no intrinsic fail-safe.
Thanks for the reply.
snafu79213:
stevech,The xbee coordinator is connected serially to my computer through an xbee explorer running a simple serial application sending and receiving api frames. The xbee end device is stand alone with its i/o set up as DOs connected to leds for testing.
I noticed that if the application shut down, the outputs stayed in their current state, not defaulting to ‘off’.
I’m planning on using the outputs to drive solenoids. I’m worried that there’s no intrinsic fail-safe.
Thanks for the reply.
I’d think that the XBee changes its GPIO bits on/off according to commands received wirelessly. So if you shut down the PC that generates commands, then the XBee merely continues the current state.
For a failsafe, you’d need a microprocessor between the XBee bits and the solenoid driver. Would that failsafe switch the solenoids to the “off” state if some sort of heartbeat message from the PC ceases?
To avoid a microprocessor, maybe you can arrange a 555 or other timer with a long delay. If it times out, it causes the solenoid drivers to switch off. You’d reset the 555 using another XBee GPIO bit that toggles before the 555 times out because of an incoming message from the PC.
Or some such.
Hey man, thanks for the help… I think the timer will work perfectly.
snafu79213:
Hey there,I’m wondering if the XBEE ZNET/ZB modules have something equivalent to the function of the Tn timer for the end device to monitor communication to the router/coordinator?
I was psyched about using these modules because of the I/O, thinking that I wouldn’t need a microcontroller. But without the failsafe, using the digital output is pretty risky.
Am I missing something?
Thanks for the help.
DB
Hello snafu, did you finally find the Tn command (T0, T1, T2, …) equivalent in ZNET modules?
That is a command from the “I/O Line Passing” inside “I/O Settings” in “Modem Configuration” in “X-CTU” software.
I need to configure the modules to work without any microcontroller, external timer (555) or any external component. It’s called “XBee Virtual Wire”
Just to push a button in a module pin and turn the LED in the other module’s pin
I was about to open a new thread but I’ll try first if something usefull appears in this thread.
Regards
Worth considering the Programmable XBee. It includes a second fully programmable microcontroller in the XBee Pro form factor. I think your timer solution is probably right for your application, but worth considering the Programmable version if you want more flexibility and/or if size is an issue in another project: