# HL7800 as a network interface in Linux

**URL:** <https://forum.sierrawireless.com/t/hl7800-as-a-network-interface-in-linux/20224>\
**Category:** HL78\
**Created:** [May 4, 2020, 9:25am UTC](https://forum.sierrawireless.com/t/hl7800-as-a-network-interface-in-linux/20224 "2020-05-04T09:25:41Z")\
**Posts on this page:** 1\
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**Author:** ![AE5000](https://sea1.discourse-cdn.com/flex025/user_avatar/forum.sierrawireless.com/ae5000/32/4828_2.png) [@AE5000](https://forum.sierrawireless.com/u/AE5000)\
**Post date:** [May 4, 2020, 2:51pm UTC](https://forum.sierrawireless.com/t/hl7800-as-a-network-interface-in-linux/20224/2 "2020-05-04T14:51:08Z")

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Hi @gustav.sohtell,

I assume that HL7800 is already in USB mode. You can confirm this with AT+KUSBCOMP? command. If it returns “1”, that means device is in USB mode.

Once in USB mode, you will see three ttyACMx ports. Typically, ttyACM0, ttyACM1 and ttyACM2.

USB-ACM0 — AT port

USB-ACM1 — AT/PPP data port

USB-ACM2 — NMEA data port

I will recommend to you ACM1 as your PPP port.

- You will also need PPP daemon installed on your host. Check that pppd is available with pppd version

- Check that your kernel is built with the ppp module: uname -a; dmesg | grep -i ppp

- Before configuring the ppp link, check first you can connect to your ISP (Internet Service Provider) manually. Send manually ATDT123 (or “ATD_99_\*\*1#” for later releases). You should get a response of “CONNECT or CONNECTED”. Then close the AT link.

- Create an /etc/chatscripts/hl78xx-chat file which contains:  
_ABORT BUSY_  
_ABORT “NO CARRIER”_  
_ABORT VOICE_  
_ABORT “NO DIALTONE”_  
_ABORT “NO ANSWER”_  
_ABORT DELAYED_  
_ABORT ERROR_  
_TIMEOUT 10_  
_“” AT_  
_OK "ATD_99\*\*_1#"_  
_CONNECT_

- Create an /etc/ppp/peers/hl78xx file which contains:

_noauth_  
_connect “/usr/sbin/chat -v -t 5 -f /etc/chatscripts/hl78xx-chat”_  
_debug_  
_/dev/ttyACM1_  
_115200_  
_defaultroute_  
_noipdefault_  
_usepeerdns_  
_lcp-echo-interval 20_  
_noaccomp_

- Launch PPP session with : sudo pppd call hl78xx

- If PPP was successfully established, “ifconfig” should show something like:

ppp0 Link encap:Point-to-Point Protocol

inet addr:10.0.0.10 P-t-P:1xx.xx.xx.xx Mask:255.255.255.255

UP POINTOPOINT RUNNING NOARP MULTICAST MTU:1500 Metric:1

RX packets:7 errors:0 dropped:0 overruns:0 frame:0

TX packets:7 errors:0 dropped:0 overruns:0 carrier:0

collisions:0 txqueuelen:3

RX bytes:345 (345.0 B) TX bytes:201 (201.0 B)

- If you have access to the embedded Linux shell, the syslog file shows very useful information about the ppp connection.

=======================

I have also uploaded PPP chatscripts that you can use.  
[PPP.7z](https://forum.sierrawireless.com/uploads/short-url/8suYBKqgoD6iaDsIabwepOs9yt7.7z) (422 Bytes)

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