AT%XRFTEST behavior

[fastfox]

I guess this should be obvious, but I still have to ask. What do XRFTEST RX and TX modes actually do? I've read the documentation and it "feels" like they command the transceiver to continuously transmit or receive signal. I say "feels" because documents are not really saying that. On the other hand, e.g the RX command returns the received power level immediately and there is no way to subscribe notification or something. So this hints that they might not leave the mode on.

What I am actually trying to achieve is to formulate some sort of test code before going to spend expensive lab time. So if I want to e.g. measure received signal level on band X do I have to call XRFTEST in a loop to get measurements in every 0.5s for example?

[Kaja]

Hi,

RX testing:
"The command enables RF receiver with the given parameters. It also measures signal power at the SiP antenna port with a time domain power meter and returns the measurement result."

TX testing:
"The command enables RF transmitter with the given parameters. It also measures TX power with an internal measurement receiver in time domain and returns the measurement result. When using TX burst mode, see TX burst mode on page 170."

So yes, with RX testing you can start the receiver. Make sure to set the correct parameters, best on what you want to test.

Tx testing you can transmit power on a frequency, again make sure you choose the correct parameters based on what you want to test. 

CAUTION: This command transmits power to the selected RF band and may violate the radio directives of the region or country. Make sure that the equipment is in an RF-shielded room or connected to an RF cable so that RF power will not leak.
Note: Some LTE bands may be supported in only one of the system modes. To ensure that the band can be used, set the correct mode with %XSYSTEMMODE.


https://infocenter.nordicsemi.com/pdf/nrf91_at_commands_v1.6.pdf

Best regards,
Kaja

[fastfox]

Hi Kaja and thanks for answering. I didn't get any wiser though Let my try to rephrase.

1) If I command modem to TX testing mode, AT command returns with internal measurement. What happens after that? Modem sends the signal as long it is commanded off? Quits after command returns? Something else?

2) If I command modem to RX testing mode, AT command returns and reports the measured RX power. What happens then? Is modem still in RX mode and receiving until I command it off? Is there a way to check what level the modem received e.g. 5 seconds after starting the test?

[Kaja]

Hi, 

it depends on what you use in the parameters. The white paper contains examples:

And yes to stop the constant carrier you need to stop it, sending TX off. 

Best regards,
Kaja