XBP09, S2 - What frequencies are the channels?

Question

The spec sheet for the XBP09-DMUIT-156 radios says that there are 12 operating channels to choose from. However XCTU allows only 1 of 8 channels to be selected.

If the radio is within the ISM range of 902MHz to 928MHz, are the channels equidistant across that frequency range spanning the whole 26MHz, or are they so many KHz apart starting at a certain base frequency, much like the S3B radios?

What is the frequency for each of the 8 channels?

Answer 1

These 900Mhz modules actually use 63 channels in US variant (12 channels is for certain S2 2.4GHZ module).

But unlike 2.4GHz modules, they use Frequency modulation for operation i.e. module will use multiple channels for transmission by hopping on one after another. What you are referring to are 8 Hopping Channels i.e. 8 different frequency hopping patterns for modulation and not sticking to particular channel.

Hope it helps.

Comments

Hi asgm, thanks for your reply.

I was asking about the frequency because I have a few networks with nodes that drop-off during the daytime for no discernible reason. When someone goes out to check the battery, it is good. In some cases power cycling the module is required. In other cases, changing the SP/ST values is enough to get them to respond again although this does not always work.

I have tried SO=2 with the first network deployed. Then adjusted this to 124 which seemed to be better, then 126 which did not seem to make much difference. I am now trying SO=12E. This seems to be making a positive difference so far.

Some networks have nodes that drop-off completely around 6:00PM. I suspect there may be radio wave reflections from other transmitters, during the approaching night time. The same as what short-wave ham operators experience? These modules sometimes do not attach to the network again, and require someone to go out and power cycle that module.

Thanks for your time and help!

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Yup, this might be because of interference from near by network. Use ATED command to check energy level on each channel and compare values when system is not working well with values collected during normal operations.