# EM7430 send AT command no response **URL:** \ **Category:** MC/EM Series\ **Created:** [September 5, 2016, 10:11am UTC](https://forum.sierrawireless.com/t/em7430-send-at-command-no-response/8772 "2016-09-05T10:11:36Z")\ **Posts on this page:** 2\ **Page:** 2
**Author:** ![vve](https://avatars.discourse-cdn.com/v4/letter/v/51bf81/32.png) [@vve](https://forum.sierrawireless.com/u/vve)\ **Post date:** [October 2, 2016, 12:37am UTC](https://forum.sierrawireless.com/t/em7430-send-at-command-no-response/8772/21 "2016-10-02T00:37:13Z")
ason0821 I’d suggest you to try the legacy linux generic usbserial driver. Before this, you have to unbind qcserial from your AT port, of course. I’ve tried to do this myself, just for verification. See how it works in my example: ```auto [root@yrgw ~]# lsusb Bus 001 Device 002: ID 1199:9071 Sierra Wireless, Inc. Bus 001 Device 001: ID 1d6b:0002 Linux Foundation Bus 005 Device 001: ID 1d6b:0001 Linux Foundation Bus 004 Device 001: ID 1d6b:0001 Linux Foundation Bus 003 Device 001: ID 1d6b:0001 Linux Foundation Bus 002 Device 001: ID 1d6b:0001 Linux Foundation [root@yrgw ~]# lsusb -t /: Bus 05.Port 1: Dev 1, Class=root_hub, Driver=uhci_hcd/2p, 12M /: Bus 04.Port 1: Dev 1, Class=root_hub, Driver=uhci_hcd/2p, 12M /: Bus 03.Port 1: Dev 1, Class=root_hub, Driver=uhci_hcd/2p, 12M /: Bus 02.Port 1: Dev 1, Class=root_hub, Driver=uhci_hcd/2p, 12M /: Bus 01.Port 1: Dev 1, Class=root_hub, Driver=ehci-pci/8p, 480M |__ Port 2: Dev 2, If 0, Class=Vendor Specific Class, Driver=qcserial, 480M |__ Port 2: Dev 2, If 2, Class=Vendor Specific Class, Driver=qcserial, 480M |__ Port 2: Dev 2, If 3, Class=Vendor Specific Class, Driver=qcserial, 480M |__ Port 2: Dev 2, If 12, Class=Communications, Driver=cdc_mbim, 480M |__ Port 2: Dev 2, If 13, Class=CDC Data, Driver=cdc_mbim, 480M [root@yrgw ~]# ls /sys/bus/usb/drivers/qcserial 1-2:1.0 1-2:1.2 1-2:1.3 bind uevent unbind [root@yrgw ~]# echo -n "1-2:1.3" > /sys/bus/usb/drivers/qcserial/unbind [root@yrgw ~]# lsusb -t /: Bus 05.Port 1: Dev 1, Class=root_hub, Driver=uhci_hcd/2p, 12M /: Bus 04.Port 1: Dev 1, Class=root_hub, Driver=uhci_hcd/2p, 12M /: Bus 03.Port 1: Dev 1, Class=root_hub, Driver=uhci_hcd/2p, 12M /: Bus 02.Port 1: Dev 1, Class=root_hub, Driver=uhci_hcd/2p, 12M /: Bus 01.Port 1: Dev 1, Class=root_hub, Driver=ehci-pci/8p, 480M |__ Port 2: Dev 2, If 0, Class=Vendor Specific Class, Driver=qcserial, 480M |__ Port 2: Dev 2, If 2, Class=Vendor Specific Class, Driver=qcserial, 480M |__ Port 2: Dev 2, If 3, Class=Vendor Specific Class, Driver=, 480M |__ Port 2: Dev 2, If 12, Class=Communications, Driver=cdc_mbim, 480M |__ Port 2: Dev 2, If 13, Class=CDC Data, Driver=cdc_mbim, 480M [root@yrgw ~]# echo 1199 9071 > /sys/bus/usb-serial/drivers/generic/new_id [root@yrgw ~]# lsusb -t /: Bus 05.Port 1: Dev 1, Class=root_hub, Driver=uhci_hcd/2p, 12M /: Bus 04.Port 1: Dev 1, Class=root_hub, Driver=uhci_hcd/2p, 12M /: Bus 03.Port 1: Dev 1, Class=root_hub, Driver=uhci_hcd/2p, 12M /: Bus 02.Port 1: Dev 1, Class=root_hub, Driver=uhci_hcd/2p, 12M /: Bus 01.Port 1: Dev 1, Class=root_hub, Driver=ehci-pci/8p, 480M |__ Port 2: Dev 2, If 0, Class=Vendor Specific Class, Driver=qcserial, 480M |__ Port 2: Dev 2, If 2, Class=Vendor Specific Class, Driver=qcserial, 480M |__ Port 2: Dev 2, If 3, Class=Vendor Specific Class, Driver=usbserial_generic, 480M |__ Port 2: Dev 2, If 12, Class=Communications, Driver=cdc_mbim, 480M |__ Port 2: Dev 2, If 13, Class=CDC Data, Driver=cdc_mbim, 480M [root@yrgw ~]# ls /dev/ttyUSB* /dev/ttyUSB0 /dev/ttyUSB1 /dev/ttyUSB2 [root@yrgw ~]# cat /dev/ttyUSB2 & [1] 15226 [root@yrgw ~]# echo 'ate0' > /dev/ttyUSB2 [root@yrgw ~]# OK [root@yrgw ~]# echo 'at!image?' > /dev/ttyUSB2 [root@yrgw ~]# TYPE SLOT STATUS LRU FAILURES UNIQUE_ID BUILD_ID FW 1 GOOD 1 0 0 ?_? 02.08.02.00_? FW 2 GOOD 127 0 0 ?_? 02.14.03.00_? FW 3 EMPTY 0 0 0 FW 4 EMPTY 0 0 0 Max FW images: 4 Active FW image is at slot 1 TYPE SLOT STATUS LRU FAILURES UNIQUE_ID BUILD_ID PRI FF GOOD 0 0 0 002.007_000 02.08.02.00_GENERIC Max PRI images: 50 OK [root@yrgw ~]# echo 'at+gmr' > /dev/ttyUSB2 [root@yrgw ~]# SWI9X30C_02.08.02.00 r5428 CARMD-EV-FRMWR2 2016/01/06 20:38:53 OK [root@yrgw ~]# ``` ---
**Author:** ![ason0821](https://avatars.discourse-cdn.com/v4/letter/a/f19dbf/32.png) [@ason0821](https://forum.sierrawireless.com/u/ason0821)\ **Post date:** [October 3, 2016, 2:16am UTC](https://forum.sierrawireless.com/t/em7430-send-at-command-no-response/8772/22 "2016-10-03T02:16:08Z")
Hi vve, Thanks for your suggestion. I found qcserial and GobiSerial that can be used to AT command, and I am porting 2.35 GobiNet work well. The root cause is our hardware team mistake that TX & RX are reversed. [Previous page](https://forum.sierrawireless.com/t/em7430-send-at-command-no-response/8772.md?page=1)