transmit testing - changing power level

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Anonymous
Not applicable

We followed this example from WICED-MFG202-R.pdf to generate a carrier wave using the mfg test app running on a BCM9433642WCD4 module:

wl --serial 99 down

wl --serial 99 country ALL

wl --serial 99 band b

wl --serial 99 mpc 0

wl --serial 99 up

wl --serial 99 out

wl --serial 99 fqacurcy 6

We see the spike with the spectrum analyzer. Then we attempted to change the power level via: txpwr1 -d 15 and also tried using milliwatts units. We cannot get the power level to change. The test app claims the power level has changed as reflected by the return value of the txpwr command, but the output on the spectrum analyzer does not change.


We also performed the modulated test from the same document:

wl --serial 99 down

wl --serial 99 country ALL

wl --serial 99 band b

wl --serial 99 chanspec -c 1 -b 2 -w 20 -s 0

wl --serial 99 mpc 0

wl --serial 99 ampdu 1

wl --serial 99 bi 65000

wl --serial 99 frameburst 1

wl --serial 99 rateset 11b

wl --serial 99 up

wl --serial 99 txant 0

wl --serial 99 antdiv 0

wl --serial 99 nrate -r 11

wl --serial 99 phy_watchdog 0

wl --serial 99 disassoc

wl --serial 99 txpwr1 -1

sleep 3

wl --serial 99 pkteng_start 00:90:4c:aa:bb:cc tx 40 1000 0

We see that the spectrum has broadened due to the modulation but the txpwr1 again has no effect in changing the actual power level.

(1) What is the correct way to change the power level for carrier wave and modulated transmit tests using the mfg test app?

(2) Is there a programmatic way to do this in our app via the WICED API?

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11 Replies
JoYi_1844281
Level 6
Level 6
100 sign-ins 100 replies posted 50 likes received

Try change power level before bring up!

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MiSp_2166266
Level 1
Level 1
Welcome!

jone

I'm am preparing device for FCC certification and also have the same problem. I also use txpwr1 command to change power, but spectrum analyzer doesn't show any changes. Changing power setting before "up" didn't help. Did you solve this problem?

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Do you check the txpwr1 command ?

See how it used for ?

Check your wl with no command!

1. Do you check the txpwr1 command ?

Yes. I checked txpwr1 command. Every time I set a new value using this command I get a confirmation from module that it was changed.

2. See how it used for ?

Yes. I was referencing document 80211-TI204-R.pdf.

3. Check your wl with no command!

Please explain what is the use of this?

txpwr1 command was used in the same manner as in flex-norcross massage. I ran the script that contained command sequence that is presented below. I've been able to see broadbanded spectrum in selected channel but no TX power changes.

echo Transmit 802.11b : Start

set comport=5

set target=43362A2

rem set target=4390A1

rem set target=43341B0

..\wl%target% --serial %comport% down

..\wl%target% --serial %comport% country ALL

..\wl%target% --serial %comport% band b

..\wl%target% --serial %comport% chanspec -c 1 -b 2 -w 20 -s 0

..\wl%target% --serial %comport% mpc 0

..\wl%target% --serial %comport% ampdu 1

..\wl%target% --serial %comport% bi 65000

..\wl%target% --serial %comport% frameburst 1

..\wl%target% --serial %comport% rateset 11b

..\wl%target% --serial %comport% up

..\wl%target% --serial %comport% txant 0

..\wl%target% --serial %comport% antdiv 0

..\wl%target% --serial %comport% nrate -r 11

..\wl%target% --serial %comport% phy_watchdog 0

..\wl%target% --serial %comport% disassoc

..\wl%target% --serial %comport% txpwr1 -d 10 -o

@echo sleep 3 seconds

@ping -n 3 127.0.0.1 > nul

..\wl%target% --serial %comport% pkteng_start 00:90:4c:aa:bb:cc tx 40 1000 0

I also tried to put txpwr1 command before up command, still no changes. Also no changes in TX power when generating carrier wave.

Can someone point to right direction how to change TX power properly.

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try bring down wifi , then change power, and bring up, to apply the new power level!

 

wlxxxx --serial 99 down

wlxxxx --serial 99 txpwr1 -d 10

wlxxxx --serial 99 up

enel_2129601
Level 3
Level 3
10 likes given 5 likes given First like received

Hi,

do you know the solution of this problem. i have same problem now.

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Anonymous
Not applicable

Hi, we do have the same problems. The tx power won't change. Any solutions? The command "txpwr1" shows the correct value (TxPower is 40 qdbm, 10.0 dbm, 10 mW  Override is Off). The Manufacturing Firmware is installed as well. We also tried to bring down the wifi, then change power, and bring it up again...

These are the issued commands:

wl down

wl country ALL

wl band b

wl mpc 0

wl up

wl phy_txpwrctrl 1

wl txpwr1 -d 10 -out

wl out

wl fqacurcy 6

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Adding the applications team anpm grsr gyan riya rroy shjl wwfe

GauravS_31
Moderator
Moderator
Moderator
10 questions asked 250 solutions authored 250 sign-ins

In general, you can use wl txpwr1 -o -d 10 in which -o is used to override the regulatory limits set in the power table. For CW testing, the transmit power cannot be changed as it is performed at constant power level and you need to be careful not to overheat the chip during this process.

So what is the Tx Power level for CW transmission? I can see the CW spike on spectrum analyzer but I'm trying to verify if device output power is correct.

-Colin

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The Tx power level will depend on the channel. The transmit power is the lower of CLM regulatory limit of the channel and board limit set in nvram. A further 1.5dB back-off is added to account for power detector uncertainty.

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