Data lags

I’m trying to make somerhing very simple, but as I’m a total noob, I think somerhing is wrong with my presets.

I just want to make a wireless serial connection between a mikrokopter and my computer. I’ve got two Xbee Pros Series 2 (zb). They work very fine for a minute, and then, the data begins to lag. I’ve set the Timeout Packetisation to 0. So, I guess my End device goes to sleep or something. But I’m pretty sure I’ve shut down the sleep mode.

What should I try next?


I’m having the same problem with Yannsolo2001.

I have one end with XBee (End Device) connected with PIC24HJ128GP210 and the other end Xbee as Coordinator at PC.

The lag can be corrected either by reset the end device XBee a few times or unplug the DC power and reconnect again.

I have disabled the sleep mode at the XBee (end device) but the problem still persists.

Is this common problem of XBee?

Hardware Specification:
XBee Pro 2
baudrate 9600, No parity, 8 bits, 1 bit stop

Can’t anybody help?

This is what I can observe.

When I switch the Coordinator ON, the green LED (RSSI) on the USB board is lit, and the red LED blinks. Nothing happens on the Rx and Tx LEDs. On the Router, the green LED is lit, the red LED blinks twice as fast as the one on the coordinator, and TX and Rx blink very fast…

At this stage, the data is quite fluid (not real time, but still ok). After a minute or so, the data stops to refresh for about a minute, then it comes back for a few seconds, and then it’s dead… The Rx led on the Router stops blinking…

Here are the Router parameters:

ID: 0
SD: 3
ZS: 0
NW: 0
JN: 0
OP: 973CA743275F55784
OI: ED03
CH: 10

NH: 1E
BH: 0
DD: 30000
NT: 3C
NO: 0
NP: 54
CR: 3
SE: E8
DE: E8
CI: 11

PL: 4
PM: 1

Serial Interfacing
BD: 6
SB: 0
RO: 0
D7: 1
D6: 0

Sleep Modes
SM: 0
SN: 1
SO: 0
SP: 20
ST 1388

I don’t think the rest is relevant…

Please, let me know if you see something that could solve my problem…

Hi! how are you?

A couple of question, are you working in AT or API mode?, the data sending is constant? (are you always sending and receiving data?).

You can make a test in AT mode : set the computer module as coordinator and set in the destination address the other module address. Set the other module has router and set the destination address high and low in 0000. I made some tests in API mode and have the same problem, but no in AT mode. Remember that the module have buffers for the sending and receiving data, is those are full the data begins to be droped!

I hope it could be useful for you!

I’ve always been in AT mode, unfortunately. So, it has to be something else…

For the record, those of us who use the Xbee pro (non ZB) have no problem.

Hi,u’d better use oscilloscope to check Xbee’s ON / SLEEP pin(pin13).I used XBP24BZ7 before,and in end device mode,the module must in one kind of sleep mode,though u set SM: 0,in fact it was in the cycle sleep mode,and pin13 will be high and low.On behalf of personal point of view.

ZigBee will add delays up to 5 seconds from time to time due to node discovery and other overhead.

ZigBee was never designed for use with “transparent streaming of data”. It was designed for small packet transactions.

Doing a simple ‘stream’ by RF is easiest by the S1/802.15.4 modules as they have no internal route maintenance.

Thanks a lot Lynn!
I’ll forget about my ZigBees an buy some S1’s.