RC7611 reports ERROR when changing KSLEEP modes (sometimes)

IoT Modules RC76
1

We use the AT command sequence “AT+KSLEEP=1” followed by “AT+KSLEEP=2” to workaround a known firmware issue with the RC76 series modems.

Recently we have observed “ERROR” in replies to this sequence. What is happening here, and how can we avoid it?

27/09/2023,12h00.07.6,log: Tx: AT
27/09/2023,12h00.07.6,log: Rx: AT
27/09/2023,12h00.07.6,log: Rx: OK
27/09/2023,12h00.07.7,log: Tx: AT+GMM
27/09/2023,12h00.07.7,log: Rx: AT+GMM
27/09/2023,12h00.07.7,log: Rx: RC7611
27/09/2023,12h00.07.7,log: Rx: OK
27/09/2023,12h00.07.7,log: Tx: ATE0
27/09/2023,12h00.07.7,log: Rx: ATE0
27/09/2023,12h00.07.7,log: Rx: OK
27/09/2023,12h00.07.7,log: Tx: AT&K3
27/09/2023,12h00.07.7,log: Rx: OK
27/09/2023,12h00.07.7,log: Tx: AT+KSLEEP=1
27/09/2023,12h00.07.7,log: Rx: OK
27/09/2023,12h00.07.7,log: Tx: AT+KSLEEP=2
27/09/2023,12h00.07.7,log: Rx: ERROR
[modem reset]
27/09/2023,12h00.15.6,log: Tx: AT
27/09/2023,12h00.15.6,log: Rx: AT
27/09/2023,12h00.15.6,log: Rx: OK
27/09/2023,12h00.15.7,log: Tx: AT+GMM
27/09/2023,12h00.15.7,log: Rx: AT+GMM
27/09/2023,12h00.15.7,log: Rx: RC7611
27/09/2023,12h00.15.7,log: Rx: OK
27/09/2023,12h00.15.7,log: Tx: ATE0
27/09/2023,12h00.15.7,log: Rx: ATE0
27/09/2023,12h00.15.7,log: Rx: OK
27/09/2023,12h00.15.7,log: Tx: AT&K3
27/09/2023,12h00.15.7,log: Rx: OK
27/09/2023,12h00.15.7,log: Tx: AT+KSLEEP=1
27/09/2023,12h00.15.7,log: Rx: OK
27/09/2023,12h00.15.7,log: Tx: AT+KSLEEP=2
27/09/2023,12h00.15.7,log: Rx: ERROR
[modem reset]
27/09/2023,12h00.31.6,log: Tx: 
27/09/2023,12h00.31.7,log: Tx: AT
27/09/2023,12h00.31.7,log: Rx: AT
27/09/2023,12h00.31.7,log: Rx: OK
27/09/2023,12h00.31.8,log: Tx: AT+GMM
27/09/2023,12h00.31.8,log: Rx: AT+GMM
27/09/2023,12h00.31.8,log: Rx: RC7611
27/09/2023,12h00.31.8,log: Rx: OK
27/09/2023,12h00.31.8,log: Tx: ATE0
27/09/2023,12h00.31.8,log: Rx: ATE0
27/09/2023,12h00.31.8,log: Rx: OK
27/09/2023,12h00.31.8,log: Tx: AT&K3
27/09/2023,12h00.31.9,log: Rx: OK
27/09/2023,12h00.31.9,log: Tx: AT+KSLEEP=1
27/09/2023,12h00.31.9,log: Rx: OK
27/09/2023,12h00.31.9,log: Tx: AT+KSLEEP=2
27/09/2023,12h00.31.9,log: Rx: OK
27/09/2023,12h00.31.9,log: Tx: AT+KSREP?
27/09/2023,12h00.31.9,log: Rx: +KSREP: 0,2
27/09/2023,12h00.31.9,log: Rx: OK

Output from ATI3:

Manufacturer: Sierra Wireless, Incorporated
Model: RC7611
Revision: SWI9X07H_00.03.03.00 2bb7a4 jenkins 2020/04/15 07:57:29
IMEI: 352138110322791
IMEI SV: 14
FSN: 6M1375318606B0
+GCAP: +CGSM
2

have you tried newer FW?

https://source.sierrawireless.com/resources/airprime/software/rc76xx/rc76xx-firmware-release-9,-d-,0/#sthash.emg6U35v.dpbs

3

Great, so the KSLEEP bug is finally fixed in release 9?

4

no, i am not quite sure if it is seen in newer FW.
that bug tracker is somehow closed without any fix…