I want to test a EM7455 when draining maximum current for a thermal design. Therefore, I wanted to use AT commands and the testmode to generate as much heat as possible. This already worked great on an MC7304 consuming up to 800 mA. Unfortunatelly I do not have a RF tester or a good LTE signal for real data transmission, so I have to rely on the AT commands.
But when trying the script below I only get a maximum current consumption of around 350 mA, although the datasheet gives a value of up to 1000 mA. Is there a known option to increase the current consumption with a AT command (e.g. a special frequency? I already tried most combinations, so I doubt that).
This is my script:
ati
Manufacturer: Sierra Wireless, Incorporated
Model: EM7455
Revision: SWI9X30C_02.24.05.06 r7040 CARMD-EV-FRMWR2 2017/05/19 06:23:09
MEID: 35907306012007
IMEI: 359073060120072
IMEI SV: 12
FSN: LF710171200110
+GCAP: +CGSM
OK
at!entercnd="A710"
OK
at!dastxoff
OK
at!usbcomp?
Config Index: 1
Config Type: 1 (Generic)
Interface bitmask: 0000100D (diag,nmea,modem,mbim)
OK
at!daftmact
OK
at!dasband=56
0
OK
at!dalstxbw=5
OK
at!dalsrxbw=5
OK
at!daschan=24440
24320
OK
at!dastxon
OK
at!dalswaveform=1,50,0,0
OK
at!dalswaveform=3,50,0,0
OK
at!dalsparange=0
0
OK
at!dalstxindex=127
OK
AT!PCTEMP?
Temp state: Normal
Temperature: 30.00 C
OK
There is a command that has not made into the manual that might help
at!dalstxpwr=,
I have shown me running factory test mode below, for some reason power 15 gives the highest current consumption of over 500mA+ constant consumption. when you do 16+ it drops back to 360/370mA.
at
OK
ati
Manufacturer: Sierra Wireless, Incorporated
Model: MC7455
Revision: SWI9X30C_02.23.00.00 r6843 CARMD-EV-FRMWR2 2016/10/22 08:55:04
MEID: 35907206005151
IMEI: 359072060051519
IMEI SV: 8
FSN: LQ545100810110
+GCAP: +CGSM
OK
at!entercnd="A710"
OK
at!daftmact
290300
OK
at!dasband=34
0
OK
at!dalstxbw=5
OK
at!dalsrxbw=5
OK
at!daschan=18300
18176
OK
at!dalstxmod=0
OK
at!dalswaveform=1,12,0,19
OK
at!dastxon
OK
at!dalstxpwr=1,10
OK
at!dalstxpwr=1,15
OK
at!dalstxpwr=1,20
OK
at!dalstxpwr=1,15
OK
at!dalstxpwr=1,18
OK
at!dalstxpwr=1,17
OK
at!dalstxpwr=1,16
OK
at!dalstxpwr=1,15
OK
We have been running temperature tests on our modem and have been trying to simulate a “Duty Cycle” using these AT commands. We have found that that the power consumption of the modem is ~1W higher when AT!DASTXOFF is run and AT!DALSTXPWR=1,22 vs. when the transmitter is OFF and AT!DALSTXPWR=0,0. I cannot find any documentation regarding what the first argument in AT!DALSTXPWR means. Why would it consume more power in AT!DALSTXPWR=1,22 with AT!DASTXOFF than AT!DALSTXPWR=0,0 when in both conditions the modem is not transmitting?