Xbee pro S3b 900HP communication problem

Question

Hello.

Some months ago I bought 2 Xbee pro 900Hp in order to establish a communication between 2 devices but I have an unknown problem and I can't send or receive information .

My circuit is composed by two microcontrollers PIC18F and two level converters https://www.sparkfun.com/products/8745.

Before send some data between the xbees , I entered to the AT mode in the xbees in order to set their DL and DH parameters to equal the SL and SH of the other module. Therefore, I did the following:

Xbee1

send the AT command (“+++”)
receive the “ok/r” answer
send the “ATSL ” <CR> word.
Receive “40A66F2A”.
send the “ATSL ” <CR> word.
Receive “13A200”.

Xbee2:
send the AT command (“+++”)
receive the “ok/r” answer
send "ATDL 40A66F2A" <CR> to set the low direction
Receive “ok/r”
send the "ATDH 13A200" <CR> to set the high direction
Receive “ok/r"
send the “ATSL ” <CR> word.
Receive “40A66F4A”.
send the “ATSL ” <CR> word.
Receive “13A200"
send "ATID 3332" <CR> to configure ID address
Receive "ok\r"
send "ATWR" to save changes
Receive "ok\r"

Xbee1:
send the AT command (“+++”)
receive the “ok/r” answer
send "ATDL 40A66F4A" <CR> low direction
Receive “ok\r”
send the "ATDH 13A200" <CR> high direction
Receive “ok\r"
send "ATID 3332" <CR> to configure ID address
Receive "ok\r"
send "ATWR" to save changes
Receive "ok\r"

Now, when I send data from any xbee, the associate led blinks faster but the other xbee does not receive data. If I replace the xbees for a cable, the communication protocol works nicely.

I am running out of ideas; if anyone can help me I would really appreciate it.


Best regards.

Róbinson Medina

Answer 1

I have solved the problem.

If you power up the xbee with 3.1 volts it doesn't work. However if you power it with 3.3 volts it start working.

Regards

Answer 2

The units will lock up in transparent mode. Digi denies the problem, but it is there. No RF out. Cable will work fine or go to the LP module. Or wait for a software fix.

Answer 3

The radios work, sometimes for months, then just stop transmitting even though data is going in to DI correctly.

Digi denies that this happens, but I can assure you it does. I have tried three different power supplies, and even the Digi development board, with the same results. My record is four months without a failure, but on the low end just six hours. The long fail time fooled me, along with assurances that these radios can't do this, so I did a job with the new radios and had some failures. At great cost to my company all radios were replaced with the low power radios and now no failures.

There is no way to recreate this problem externally. I have tried everything. It is a bug in the Digi software. Beware of these radios. Digi tech support will not help you.