TCP Connection in Mango OH(RED)


I am using Mang OH(RED) . series is HL7650.
can you please guide to me ,how can i connect to TCP connection using AT commands.


Download AT command guide here :
(make sure you are logged in before)

And check chapter 12 for the AT command description + 18.5 for examples.


hi how can i connect Mang OH(RED) to raspberry pi with the UART communication.
because of Raspberry Pi GPIO pin voltage is 3V, but MangOH GPIO voltage is 1.8V.


There is a level shifter on the mangOH Rpi connector that up converts to 3.3V.


sir level shifter means IOT expansion card that is a level shifter or something any


Level shifter convert 1.8V signal to 3.3V for the Rpi interface


yes, I got this working over the RPi connector. I am in the process of trying to connect to a webserver via AT commands, so lets see what happens.


Will these commands work with a WP8548? I am trying them but I keep getting “error” when trying to setup the TCP connection ( and I know I am connected to the APN because I can ssh into the device and see the results from cm data and see the sensor data from it on air vantage). Are there different AT commands for the WP chips?


Hi Alex,
For WP series, you need to make use of the Linux TCP/IP stack/sockets.
WP are meant to be driven from APIs and not from AT cmds anymore.
Still, there are many AT commands available that can be useful for debug/test purpose and overtime the API set ie being enriched by new ones.


Ok. Thanks. That is what I thought. My SIM card should be here today or tomorrow so I’ll just wait for that. Thanks again for all your help !!


Hi dpm,
I got my CAT M1 SIM card (It is an Aeris Neo). I am working on trying to send data to a web server, via TCP. I am using an HL7748, which I don’t see much about on the forums. Everything looks good when I register it to the network, etc. I set the APN with +cgdcont, and +creg, +cops, and +csq replies look good. I also can send the command to get the IP address, and it looks good too. I have a document, that is “Airprime HL 76XX AT Command Interface Guide”. This was sent to me by my Sierra distributor. There is a TCP example for client mode in section 18.5.1, but when I try these commands ( like AT+KCNXCFG and AT+KTCPCFG) I get an error. Perhaps I have an error in some of my arguments for the AT+KCNXCFG command, but I have tried lots of combinations. Before I try these commands from that example, I use the at+cgdcont command for the APN, the at+cgatt to attach,and then the at&k3. All these commands work and give expected responses. I assume I am missing something, but I am not sure what it is. I have gone through that AT command document and tried other commands from the TCP section, but all I get is error.


Did you ever get the TCP connection working on this chip?


I’m still having no luck with getting a TCP connection on the HL7748. The AT command document for the HL 7748 does not have anything about TCP commands, like the document you referenced. I am trying the commands in the hl76xx document but all I get is error…the HL7748 has to support TCP connection, but should I be able to use the same commands that are in the hl76xx document? I did see something in section 1.4.2 about getting an error if CID=1 is locked by +HBHV, but when I try test and read commands for +HBHV I get ERROR. I’m waiting on a response from the ticket my distributor logged, but who knows how long that will take…


Hi Alex,
I’m not familiar with the HL7748, but as far as I could see in the AT cmd guide, there are indeed no AT commands for TCP/IP stack. I will check further.
Can you send at+cmee=1 and then send the at command and see the error code returned.

BTW, this topic should be raised into the this generic Sierra forum as your question here is not linked to the mangoh board :wink:


Ok. I will get this to you ASAP!!! Sorry for the incorrect forum post. I am using the HL7748 in the mangOH red, so thought I could post here too? I have also posted in the main Sierra forum with no response. I’m trying everthing I can lol.


That was very helpful. This is my first time working with cellular/AT commands, so to get more detailed error info is good. I got an error code of ‘4’, which means not supported. So, perhaps I can talk to a web server using a different command. I will just keep trying stuff, but at least I will have more visibility now. There has to be a way to talk to a web server with it, I just need to find the correct commands. Thanks for that suggestion!!


Hi Alex
yes AT commands can tell you a lot.
Usually, while developing cellular IoT app, I recommend the following set of AT commands
at+cgreg=1 or 2
at+cmee=1 or 2
at+wdsi=8191 (if you want to test FOTA)
At&w to store in NV memory and keep configuration even after power cycle.

The some specific features have specific error codes. Specific to each features. The AT command is yor friend.

Coming back to the data session: don’t you have a TCP/IP stack in your µC. In such case, you can use PPP dialup to setup data session and use TCP or UDP sockets from your µC


My uC does not have TCP stack. I am using an Atmel uC. When I was originally sent the mangOH red board, it had a WP8548 with it. Then I was sent the HL7748 (which will be in the actual product). I was using the WP chip to at least get some code written on my uC while I waited for my CAT M1 SIM card for my HL. I did receive an email today from distributor and they got a response to ticket. I think I need a new firmware update to support TCP commands. So I will see if that works.