I need to keep xbee awake for RS232 communication and cyclic sleep mode

XBee & XBee Gateway XBee Programamble (S2C & 900 HP)
, , , ,
1

Hello,
I have a system which is powered by a relay activated by a xbee module. The system is on battery, so I need to make a cyclic sleep on the xbee card to save power.

The difficulty is that I want to make RS232 connection when the system is powered. the problem is that the xbee stay in cyclic sleep while the rest of the system try to communicate.
I don’t know how to proceed to make it.
I’ve tried SM=5 and many things but it doesn’t work…
Do you have any simple idea to keep the xbee end device activated when I need?
I use XCTU to configure it.
Do I have to make an electrical connection on a special pin to leave on request the cyclic sleep mode?

Thanks for your answers,
Regards,
Bruno

2

Sounds like you need to use CTS flow control and the On Sleep pin.

Use the On Sleep pin to power your external device when the radio is awake and use CTS to know when the radio can send and receive data via the UART.

3

Thanks for your answer, but It sounds like i didn’t gave enough details :

It’s a measurement system.
I use the xbee for communication between the measure card and my HMI on my PC.
The embedded system is composed of the measure card and an xbee card. xbee is connected via RS22 to the measure card. I recently added a distance switch (using DI03 with a relay to power on the system).

Then, I added a cyclic sleep mode to save battery on the system. The system sleeps one minute and awake one sec… so I can’t wait one minute for each measure to be received in my HMI (even if it would be 5 sec, I have to get 19K2 communication in “real time”). I need to keep the xbee “on” or to leave the sleep mode when the measure card is powered : my HMI can configure the measure card, i ve a measure scan etc… so the RS232 needs to be available sometimes during some hours.

May be i need to leave sleep mode via RS232 communicatio to change parameters each time I use the system?
But I was thinking there were maybe an electrical way like pin 9 (to send 3.3Vcc somewhere on the module and to get the sleep off?) available whith a relay or something like this to maintain xbee awake…

What i undertand of your answer is that I need to wait when the xbee is available before sending datas… I would like to do the opposite way : to get the module available when the system is powered on… is it possible (I don’t have yet any pic or arduino into the system)…

4

Sounds like you are either going to need to increase your wake time or turn off sleep mode all together.

1 Like
5

ok, that’s what I want to do : turn off sleep mode. Can I do it by a DIO or something like this (by an electrical way?)
thanks for your help…

6

No, you are going to need to disable it just like you enabled it. By Entering command mode and issuing an AT command…

7

ok, that’s the way I have to take. I ve done parameters into x-ctu, but I need an interface in my HMI program (Delphi) to send AT commands, i’m going to do this… Thanks

Thank you very much,