Response Time in GSM modem RC7620 for Some of AT commands

1

For some of AT commands what is response time need to wait

2

commands like AT,AT+CSQ?,AT_+CREG,AT+CGATT ect

3

please see RC76xx AT command user guide- Section “A.3 Command Timeout and Other Information”:
https://source.sierrawireless.com/resources/airprime/software/rc76xx-at-command-reference-guide/#sthash.HIcRE0bm.dpbs

4

Thank you for Refering this section,with this i have query of for sending just at command ,i have to wait 2 second to get response as OK from gsm modem

5

this is just the maximum value for timeout

6

okay with minimum time how fast i can get response for AT command

7

I just tried in UART:

[2025-09-22 17:46:54.320] at
[2025-09-22 17:46:54.603] OK
[2025-09-22 17:46:55.449] ati3
[2025-09-22 17:46:55.877] Manufacturer: Sierra Wireless, Incorporated
[2025-09-22 17:46:55.877] Model: RC7620-1
[2025-09-22 17:46:55.877] Revision: SWI9X07H_00.09.10.00 85890e jenkins 2023/09/25 03:16:56
[2025-09-22 17:46:55.893] IMEI: 353635110212345
[2025-09-22 17:46:55.893] IMEI SV: 29
[2025-09-22 17:46:55.893] FSN: 7T118701512345
[2025-09-22 17:46:55.893] +GCAP: +CGSM
[2025-09-22 17:46:55.893] 
[2025-09-22 17:46:55.893] OK
8

from above reference its taking around 300 ms for getting response for AT command

9

is ther any possibility to get at command response in micro second

10

if you use USB AT port, the response will be faster:


[2025-09-24 12:21:31.934] at
[2025-09-24 12:21:32.066] OK
[2025-09-24 12:21:32.887] ati3
[2025-09-24 12:21:32.890] Manufacturer: Sierra Wireless, Incorporated
[2025-09-24 12:21:32.890] Model: RC7620-1
[2025-09-24 12:21:32.890] Revision: SWI9X07H_00.09.10.00 85890e jenkins 2023/09/25 03:16:56
[2025-09-24 12:21:32.890] IMEI: 353635110212435
[2025-09-24 12:21:32.890] IMEI SV: 29
[2025-09-24 12:21:32.890] FSN: 7T118701512345
[2025-09-24 12:21:32.890] +GCAP: +CGSM
[2025-09-24 12:21:32.890] 
[2025-09-24 12:21:32.890] OK
11

for USB port also its taking around 130 ms ,is it any way to read response in micro second

12

did you do any test on your side with USB port?

Tried again with tera term with USB port by directly pasting AT commands instead of typing manually:

[2025-09-24 12:39:39.962] AT
[2025-09-24 12:39:39.962] OK
[2025-09-24 12:39:40.780] at
[2025-09-24 12:39:40.780] OK
[2025-09-24 12:39:41.585] at
[2025-09-24 12:39:41.585] OK
[2025-09-24 12:39:42.398] at
[2025-09-24 12:39:42.398] OK
[2025-09-24 12:39:43.214] at
[2025-09-24 12:39:43.214] OK
13

Basically we are interface ths GSM modem with microcontroller through UART.in this interface i am unable to receive response in micro second

14

tried again on UART with tera term by directly pasting AT commands instead of typing manually


[2025-09-24 12:54:43.413] AT
[2025-09-24 12:54:43.413] OK
[2025-09-24 12:54:44.245] at
[2025-09-24 12:54:44.245] OK
[2025-09-24 12:54:45.028] at
[2025-09-24 12:54:45.045] OK
[2025-09-24 12:54:45.845] at
[2025-09-24 12:54:45.845] OK
[2025-09-24 12:54:46.661] at
[2025-09-24 12:54:46.661] OK
15

BTW, you might also need to increase UART baud rate (e.g. 921600) by AT+IPR command and see if there is any improvement.

16

this command was unable to find in data sheet

17

can u please refer datasheet for RC7620 gsm modem with all command included

18

AT+IPR is a standard command from 3GPP specification:
https://portal.3gpp.org/desktopmodules/Specifications/SpecificationDetails.aspx?specificationId=1515

RC76 AT command user guide will not include all the standard command usage, but you can have a look here:

https://m2msupport.net/m2msupport/general-at-commands/

19

okay Thank you. currently I’m using UDP packet transfer protocol. which are the essential command i need to check every time before sending data to server.

currently i am using AT+CSQ to check signal strength

AT+CREG? to check network registered to home or its roaming

AT+CGATT? for modem status attached with gprs

for me these commands taking near 1 second

20

here is my testing in UART:


[2025-09-25 12:43:04.046] AT+CSQ
[2025-09-25 12:43:04.046] +CSQ: 26,99
[2025-09-25 12:43:04.046] 
[2025-09-25 12:43:04.046] OK
[2025-09-25 12:43:04.864] AT+CREG?
[2025-09-25 12:43:04.864] +CREG: 2,1,"FFFE","16E8A17",7
[2025-09-25 12:43:04.864] 
[2025-09-25 12:43:04.864] OK
[2025-09-25 12:43:05.663] AT+CGATT?
[2025-09-25 12:43:05.663] +CGATT: 1
[2025-09-25 12:43:05.663] 
[2025-09-25 12:43:05.663] OK
[2025-09-25 12:44:17.307] at+CSQ;+CREG?;+CGATT?
[2025-09-25 12:44:18.044] +CSQ: 24,99
[2025-09-25 12:44:18.044] 
[2025-09-25 12:44:18.044] +CREG: 2,1,"FFFE","16E8A17",7
[2025-09-25 12:44:18.044] 
[2025-09-25 12:44:18.044] +CGATT: 1
[2025-09-25 12:44:18.044] 
[2025-09-25 12:44:18.044] OK