# Knowledge Base **URL:** https://forum.sierrawireless.com/c/knowledge-base/6.md [Latest](https://forum.sierrawireless.com/latest.md) · [Categories](https://forum.sierrawireless.com/categories.md) · [Tags](https://forum.sierrawireless.com/tags.md) --- ## [About the Knowledge Base category](https://forum.sierrawireless.com/t/about-the-knowledge-base-category/12)
**Author:** [@system](https://forum.sierrawireless.com/u/system)\ **Replies:** 0\ **Last updated:** [March 16, 2018, 10:48am UTC](https://forum.sierrawireless.com/t/about-the-knowledge-base-category/12 "2018-03-16T10:48:21Z")
Articles published by Sierra products teams in order to build a knowledge base of most common features and applications. --- ## [Knowledge database policy](https://forum.sierrawireless.com/t/knowledge-database-policy/6238)
**Author:** [@Moderator1](https://forum.sierrawireless.com/u/Moderator1)\ **Replies:** 0\ **Last updated:** [April 3, 2013, 6:55am UTC](https://forum.sierrawireless.com/t/knowledge-database-policy/6238 "2013-04-03T06:55:56Z")
Knowledge database policy: In this section, you will find useful technical information posted by Sierra Wireless technical experts. Please feel free to reply to the posts, as your feedback will allow us to improve thes… --- ## [\[Hilo\] How to decode PLMN in the result of KCELL?](https://forum.sierrawireless.com/t/hilo-how-to-decode-plmn-in-the-result-of-kcell/6466)
**Author:** [@FAQ\_Poster](https://forum.sierrawireless.com/u/FAQ_Poster)\ **Replies:** 1\ **Last updated:** [March 26, 2018, 12:30pm UTC](https://forum.sierrawireless.com/t/hilo-how-to-decode-plmn-in-the-result-of-kcell/6466 "2018-03-26T12:30:36Z")
Answer: In the response of \, the PLMN format is the one defined in the 3GPP. It is coded as following: With 2 digits MNC: PLMN = MCC\[2\] MCC\[1\] F MCC\[3\] MNC\[2\] MNC\[1\] With 3 digits MNC: PLMN = MCC\[2\] MCC\[1\]… --- ## [Knowledge database policy](https://forum.sierrawireless.com/t/knowledge-database-policy/6438)
**Author:** [@Moderator1](https://forum.sierrawireless.com/u/Moderator1)\ **Replies:** 2\ **Last updated:** [November 29, 2017, 2:59am UTC](https://forum.sierrawireless.com/t/knowledge-database-policy/6438 "2017-11-29T02:59:25Z")
Knowledge database policy: In this section, you will find useful technical information posted by Sierra Wireless technical experts. Please feel free to reply to the posts, as your feedback will allow us to improve thes… --- ## [Can I get a Static IP for the GX440 on the VZW and AT&T LTE](https://forum.sierrawireless.com/t/can-i-get-a-static-ip-for-the-gx440-on-the-vzw-and-at-t-lte/5937)
**Author:** [@FAQ\_Poster](https://forum.sierrawireless.com/u/FAQ_Poster)\ **Replies:** 2\ **Last updated:** [July 26, 2017, 5:13pm UTC](https://forum.sierrawireless.com/t/can-i-get-a-static-ip-for-the-gx440-on-the-vzw-and-at-t-lte/5937 "2017-07-26T17:13:45Z")
Yes, you can get a static IP on the VZW LTE network by working with your VZW representative. Yes, you can get a static IP on the AT&T LTE network with a custom APN. Please work with your AT&T representative. --- ## [SMS is not sent immediately](https://forum.sierrawireless.com/t/sms-is-not-sent-immediately/6143)
**Author:** [@FAQ\_Poster](https://forum.sierrawireless.com/u/FAQ_Poster)\ **Replies:** 1\ **Last updated:** [July 19, 2017, 11:37am UTC](https://forum.sierrawireless.com/t/sms-is-not-sent-immediately/6143 "2017-07-19T11:37:26Z")
Background Minicards and SL80xx modems are customized to attempt to send SMS multiple times. In case when SMS is not sent immediately, modem will attempt to send SMS again after predefined wait interval has elapsed. AT!… --- ## [Reverse SSH to a Serial Device behind AirLink device](https://forum.sierrawireless.com/t/reverse-ssh-to-a-serial-device-behind-airlink-device/7522)
**Author:** [@FAQ\_Poster](https://forum.sierrawireless.com/u/FAQ_Poster)\ **Replies:** 1\ **Last updated:** [July 12, 2017, 4:54pm UTC](https://forum.sierrawireless.com/t/reverse-ssh-to-a-serial-device-behind-airlink-device/7522 "2017-07-12T16:54:54Z")
This article applies to ES440, GX400, GX440 and LS300 AirLink devices. How to establish a Reverse SSH to a Serial Device behind the AirLink device --- ## [Configuring IP to Serial with Auto Answer and Serial to IP](https://forum.sierrawireless.com/t/configuring-ip-to-serial-with-auto-answer-and-serial-to-ip/7851)
**Author:** [@FAQ\_Poster](https://forum.sierrawireless.com/u/FAQ_Poster)\ **Replies:** 0\ **Last updated:** [March 31, 2015, 10:17pm UTC](https://forum.sierrawireless.com/t/configuring-ip-to-serial-with-auto-answer-and-serial-to-ip/7851 "2015-03-31T22:17:07Z")
This article applies for GX Series devices. Configuring IP to Serial with Auto Answer and Serial to IP --- ## [How to test sending SMS Messages with Airlink IP Protocol](https://forum.sierrawireless.com/t/how-to-test-sending-sms-messages-with-airlink-ip-protocol/7520)
**Author:** [@FAQ\_Poster](https://forum.sierrawireless.com/u/FAQ_Poster)\ **Replies:** 0\ **Last updated:** [October 29, 2014, 11:07pm UTC](https://forum.sierrawireless.com/t/how-to-test-sending-sms-messages-with-airlink-ip-protocol/7520 "2014-10-29T23:07:30Z")
How to test sending SMS Messages with Airlink IP Protocol --- ## [How to wire DC Power cord for the LS300 and GX Series](https://forum.sierrawireless.com/t/how-to-wire-dc-power-cord-for-the-ls300-and-gx-series/7510)
**Author:** [@FAQ\_Poster](https://forum.sierrawireless.com/u/FAQ_Poster)\ **Replies:** 0\ **Last updated:** [October 23, 2014, 11:34pm UTC](https://forum.sierrawireless.com/t/how-to-wire-dc-power-cord-for-the-ls300-and-gx-series/7510 "2014-10-23T23:34:37Z")
For LS300, GX440, and GX440 modems Please click on link below: What is the wiring assembly for the DC power cord for the LS300 and GX Series Modems? --- ## [How to send SMS Messages with AT Commands?](https://forum.sierrawireless.com/t/how-to-send-sms-messages-with-at-commands/7501)
**Author:** [@FAQ\_Poster](https://forum.sierrawireless.com/u/FAQ_Poster)\ **Replies:** 0\ **Last updated:** [October 17, 2014, 7:47pm UTC](https://forum.sierrawireless.com/t/how-to-send-sms-messages-with-at-commands/7501 "2014-10-17T19:47:47Z")
This article applies for GX400, GX440, LS300, Raven X series and PinPoint X series modems How to send SMS messages with an AirLink device using AT commands? --- ## [Advisory on CVE-2014-6271 “ShellShock” for AirLink products](https://forum.sierrawireless.com/t/advisory-on-cve-2014-6271-shellshock-for-airlink-products/7477)
**Author:** [@FAQ\_Poster](https://forum.sierrawireless.com/u/FAQ_Poster)\ **Replies:** 0\ **Last updated:** [October 2, 2014, 10:10pm UTC](https://forum.sierrawireless.com/t/advisory-on-cve-2014-6271-shellshock-for-airlink-products/7477 "2014-10-02T22:10:56Z")
Advisory on CVE-2014-6271 “ShellShock” for AirLink products --- ## [WAN Failover with Cisco 881 Router and an AirLink ES440](https://forum.sierrawireless.com/t/wan-failover-with-cisco-881-router-and-an-airlink-es440/7465)
**Author:** [@FAQ\_Poster](https://forum.sierrawireless.com/u/FAQ_Poster)\ **Replies:** 0\ **Last updated:** [September 29, 2014, 7:28pm UTC](https://forum.sierrawireless.com/t/wan-failover-with-cisco-881-router-and-an-airlink-es440/7465 "2014-09-29T19:28:32Z")
Configuring WAN Failover with a Cisco 881 Router and an AirLink ES440 For more information please click on link below: Configuring WAN Failover with a Cisco 881 Router and an AirLink ES440 --- ## [Is it necessary to use both SMA RF antennas on GX400?](https://forum.sierrawireless.com/t/is-it-necessary-to-use-both-sma-rf-antennas-on-gx400/7448)
**Author:** [@FAQ\_Poster](https://forum.sierrawireless.com/u/FAQ_Poster)\ **Replies:** 0\ **Last updated:** [September 19, 2014, 8:21pm UTC](https://forum.sierrawireless.com/t/is-it-necessary-to-use-both-sma-rf-antennas-on-gx400/7448 "2014-09-19T20:21:46Z")
The additional antenna port on the GX400 (EVDO and HSPA+) are for Rx Diversity. Rx Diversity is designed to improve the quality of the downlink signal by essentially enabling the device to “choose” the best available sig… --- ## [How to test Reverse Telnet](https://forum.sierrawireless.com/t/how-to-test-reverse-telnet/7436)
**Author:** [@FAQ\_Poster](https://forum.sierrawireless.com/u/FAQ_Poster)\ **Replies:** 0\ **Last updated:** [September 16, 2014, 9:16pm UTC](https://forum.sierrawireless.com/t/how-to-test-reverse-telnet/7436 "2014-09-16T21:16:20Z")
This article applies for ES440, GX440 and LS300 AirLink modems. Cable required When using a blue console cable to connect to a Cisco router, you must use an additional NULL modem DB9 adapter, ending in a DB9 Male conne… --- ## [\[Hilo\] How to know the HW variant of the HL6528?](https://forum.sierrawireless.com/t/hilo-how-to-know-the-hw-variant-of-the-hl6528/6930)
**Author:** [@FAQ\_Poster](https://forum.sierrawireless.com/u/FAQ_Poster)\ **Replies:** 0\ **Last updated:** [December 19, 2013, 2:45am UTC](https://forum.sierrawireless.com/t/hilo-how-to-know-the-hw-variant-of-the-hl6528/6930 "2013-12-19T02:45:53Z")
Answer: We have four variants of HL6528 as following: Without GNSS : 1.8v HL6528 (GX) 2.8v HL6528-2.8V (GW) With GNSS : 1.8v HL6528-G (GZ) 2.8v HL6528-G2.8V (GY) We can know the HW variant by sending AT+KGSN=3, for … --- ## [Is it necessary to use both SMA RF antennas on a GX440/ES440](https://forum.sierrawireless.com/t/is-it-necessary-to-use-both-sma-rf-antennas-on-a-gx440-es440/5944)
**Author:** [@FAQ\_Poster](https://forum.sierrawireless.com/u/FAQ_Poster)\ **Replies:** 1\ **Last updated:** [December 1, 2013, 6:48pm UTC](https://forum.sierrawireless.com/t/is-it-necessary-to-use-both-sma-rf-antennas-on-a-gx440-es440/5944 "2013-12-01T18:48:39Z")
The GX440/ES440 (LTE) utilizes 2x2 MIMO technology. MIMO equals Multi-In/Multi-out and is designed to improve the cellular signal and quality on both the down-link and up-link. MIMO for LTE works differently than Rx Dive… --- ## [What X-Cards are available for GX400 & GX440 expansion slots](https://forum.sierrawireless.com/t/what-x-cards-are-available-for-gx400-gx440-expansion-slots/5945)
**Author:** [@FAQ\_Poster](https://forum.sierrawireless.com/u/FAQ_Poster)\ **Replies:** 3\ **Last updated:** [August 23, 2013, 12:57pm UTC](https://forum.sierrawireless.com/t/what-x-cards-are-available-for-gx400-gx440-expansion-slots/5945 "2013-08-23T12:57:40Z")
Both GX devices have an expansion card slot, which will greatly increase the versatility of the platform. As of AUG 2012 Sierra Wireless has a WiFi XCard that will enables a WiFi (802.11 b/g/n) hotspot (access point) an… --- ## [\[Hilo\]How to upgrade module via host CPU?](https://forum.sierrawireless.com/t/hilo-how-to-upgrade-module-via-host-cpu/6660)
**Author:** [@FAQ\_Poster](https://forum.sierrawireless.com/u/FAQ_Poster)\ **Replies:** 0\ **Last updated:** [August 6, 2013, 9:28am UTC](https://forum.sierrawireless.com/t/hilo-how-to-upgrade-module-via-host-cpu/6660 "2013-08-06T09:28:19Z")
\[Hilo\] How to use my CPU as a gateway between the module and a PC to upgrade via HiloUpgrader? Answer: Let me sum up the conditions to upgrade the module via your CPU as a gateway. 1/ The baud rate must be 115200 baud. … --- ## [\[Hilo\] right way for SIM switching](https://forum.sierrawireless.com/t/hilo-right-way-for-sim-switching/6641)
**Author:** [@FAQ\_Poster](https://forum.sierrawireless.com/u/FAQ_Poster)\ **Replies:** 0\ **Last updated:** [July 24, 2013, 9:44am UTC](https://forum.sierrawireless.com/t/hilo-right-way-for-sim-switching/6641 "2013-07-24T09:44:45Z")
\[Hilo\] We need to support dual SIM card holders in HiloV2. What is the right way for SIM switching and get modem in service again? Answer: Please power off and then switch the SIM card. And there’s two ways to get modem… --- ## [\[Hilo\] What can be the maximum voltage on VBAT signal?](https://forum.sierrawireless.com/t/hilo-what-can-be-the-maximum-voltage-on-vbat-signal/6639)
**Author:** [@FAQ\_Poster](https://forum.sierrawireless.com/u/FAQ_Poster)\ **Replies:** 0\ **Last updated:** [July 24, 2013, 7:59am UTC](https://forum.sierrawireless.com/t/hilo-what-can-be-the-maximum-voltage-on-vbat-signal/6639 "2013-07-24T07:59:01Z")
Answer: Absolute max voltage for supply HiloV2: “5.1 Vbat”: Vbat MAX 4,5V URD1\_OTL\_5635\_2\_013\_72398\_ed\_02\_-\_HiLo\_V2\_technical\_specification\_14\_March\_2011.pdf Hilo3G: “5.1 Vbat”: Vbat MAX 4,4V URD1\_OTL\_5696\_1\_004\_7236… --- ## [\[Hilo\] What is the MAX current consumption for USB?](https://forum.sierrawireless.com/t/hilo-what-is-the-max-current-consumption-for-usb/6638)
**Author:** [@FAQ\_Poster](https://forum.sierrawireless.com/u/FAQ_Poster)\ **Replies:** 0\ **Last updated:** [July 24, 2013, 7:58am UTC](https://forum.sierrawireless.com/t/hilo-what-is-the-max-current-consumption-for-usb/6638 "2013-07-24T07:58:09Z")
\[Hilo\] What is the MAX current consumption for USB in HIlo3G? Answer: The HiLo3G is USB-Slave, it don’t supply current. Like specified in the technical specification, here’s some information: An USB link is available f… --- ## [\[Hilo\] analog audio signals Vs. digital audio](https://forum.sierrawireless.com/t/hilo-analog-audio-signals-vs-digital-audio/6637)
**Author:** [@FAQ\_Poster](https://forum.sierrawireless.com/u/FAQ_Poster)\ **Replies:** 0\ **Last updated:** [July 24, 2013, 7:56am UTC](https://forum.sierrawireless.com/t/hilo-analog-audio-signals-vs-digital-audio/6637 "2013-07-24T07:56:43Z")
\[Hilo\] Do you know if analog audio signals are more subject to external perturbation from other radio signals (in comparison with digital audio)? Indeed our analog SLIC or audio path seems sensitive to external radio sig… --- ## [\[Hilo\]Current consumption in low/high temperature](https://forum.sierrawireless.com/t/hilo-current-consumption-in-low-high-temperature/6636)
**Author:** [@FAQ\_Poster](https://forum.sierrawireless.com/u/FAQ_Poster)\ **Replies:** 0\ **Last updated:** [July 24, 2013, 7:54am UTC](https://forum.sierrawireless.com/t/hilo-current-consumption-in-low-high-temperature/6636 "2013-07-24T07:54:54Z")
\[Hilo\] What is the Current consumption in low/high temperature and during voice/ecall communication? Answer: The current consumption is (in mA): max -40°C 25°C +85°C gsm (PCL=5) F5 250 250 gprs (PCL=5) 445 455 455 e… --- ## [\[Hilo\] about CTS/RTS timing](https://forum.sierrawireless.com/t/hilo-about-cts-rts-timing/6635)
**Author:** [@FAQ\_Poster](https://forum.sierrawireless.com/u/FAQ_Poster)\ **Replies:** 0\ **Last updated:** [July 24, 2013, 7:52am UTC](https://forum.sierrawireless.com/t/hilo-about-cts-rts-timing/6635 "2013-07-24T07:52:56Z")
\[Hilo\] GPS Standard is using HiLoNC V2 FW 3.00 with RTS/CTS HW flow control enabled. The host processor do not have buffer on UART and it generates an RTS Low (+V) at each character when it sends AT command, modules rep… --- ## [\[Hilo\] default configuration of GPIO for HiloV1 module](https://forum.sierrawireless.com/t/hilo-default-configuration-of-gpio-for-hilov1-module/6634)
**Author:** [@FAQ\_Poster](https://forum.sierrawireless.com/u/FAQ_Poster)\ **Replies:** 0\ **Last updated:** [July 24, 2013, 7:49am UTC](https://forum.sierrawireless.com/t/hilo-default-configuration-of-gpio-for-hilov1-module/6634 "2013-07-24T07:49:47Z")
\[Hilo\] For HiloV1, What is the default configuration of all GPIOs at power up? Answer: All GPIOs have internal pull up and pull down except GPIO4 and GPIO5. GPIO4 and GPIO5 is open collector and need external pull up. … --- ## [\[Hilo\] what is the 5V-Connection (VUSB) at Hilo3G?](https://forum.sierrawireless.com/t/hilo-what-is-the-5v-connection-vusb-at-hilo3g/6633)
**Author:** [@FAQ\_Poster](https://forum.sierrawireless.com/u/FAQ_Poster)\ **Replies:** 0\ **Last updated:** [July 24, 2013, 7:48am UTC](https://forum.sierrawireless.com/t/hilo-what-is-the-5v-connection-vusb-at-hilo3g/6633 "2013-07-24T07:48:11Z")
\[Hilo\] what is the 5V-Connection (VUSB) at Hilo3G? Is it activating the USB-interface? Or does the 5V-Connection (VUSB) supply the module with power? Answer: Our USB interface follows the USB standard. VUSB is used as … --- ## [\[Hilo\] advantages using PCM instead of analog signals](https://forum.sierrawireless.com/t/hilo-advantages-using-pcm-instead-of-analog-signals/6632)
**Author:** [@FAQ\_Poster](https://forum.sierrawireless.com/u/FAQ_Poster)\ **Replies:** 0\ **Last updated:** [July 24, 2013, 7:47am UTC](https://forum.sierrawireless.com/t/hilo-advantages-using-pcm-instead-of-analog-signals/6632 "2013-07-24T07:47:28Z")
\[Hilo\] \[PCM\] what are the advantages of using PCM instead of analog signals? Answer: For using the digital audio path (PCM) you have to add one chip to convert digital to analog then you can plug your mic and speaker. I… --- ## [\[Hilo\] Does pin\_41(POK\_IN) is active high or low?](https://forum.sierrawireless.com/t/hilo-does-pin-41-pok-in-is-active-high-or-low/6631)
**Author:** [@FAQ\_Poster](https://forum.sierrawireless.com/u/FAQ_Poster)\ **Replies:** 0\ **Last updated:** [July 24, 2013, 6:37am UTC](https://forum.sierrawireless.com/t/hilo-does-pin-41-pok-in-is-active-high-or-low/6631 "2013-07-24T06:37:39Z")
Answer: It is low (electrical) level active with an internal pull up of 47K to an internal 3V power domain, thus only requiring an open drain or open collector transistor to be controlled. --- ## [\[Hilo\] Any dedicated Analog GND pins for audio input?](https://forum.sierrawireless.com/t/hilo-any-dedicated-analog-gnd-pins-for-audio-input/6630)
**Author:** [@FAQ\_Poster](https://forum.sierrawireless.com/u/FAQ_Poster)\ **Replies:** 0\ **Last updated:** [July 24, 2013, 6:36am UTC](https://forum.sierrawireless.com/t/hilo-any-dedicated-analog-gnd-pins-for-audio-input/6630 "2013-07-24T06:36:30Z")
Answer: Yes Pin 3 is the closest ground that internally surrounds the audio parts and is connected to the main ground in a single area to avoid noise spread. The audio GND pin 3 is internally linked to the main ground. [Next page](https://forum.sierrawireless.com/c/knowledge-base/6.md?page=1)