Hello,
I do MQTT communication between a FLEXY 205 (Firmware Version 13.0s0) and Azure IoT HUB.
I am looking for a way to detect that there is a problem with the communication (Internet or MQTT) to not lose any transfer.
When I have a communication problem, I will save the data in a file and I will retransfer it later when the communication is back.
Do you have any idea of the information I need to use to make the change based on the state of the communication.
Thank you
Christian
Hi Christian,
Are you worried about communication loss just between the devices or communication with the internet? Also are you using ethernet/wifi/3G/4G?
-Tim
Hi Tim,
I want to detect the possible losses of communication between Flexy and Azure Iot HUB as well as Internet losses.
I have several devices and I use all types of communication (ethernet / wifi / 3G / 4G).
If I use MQTT “PUBLISH” with QoS = 1, is it possible to read the answer to make sure the communication was successful?
Thank you
Christian
Hi Christian,
I found an answer to the Internet loss question, but unfortunately you’ll need to have a Talk2M pro account.
I’m still working on checking the connection between a flexy and a device
-Tim
I think this should help you check connection between your device and the flexy. It checks to see if the device is responding to pings and will send out a message if there is no response.
Let me know if this solution works for you.
-Tim
Hello Tim,
It does not not really what I need 
Here are the instructions that I use to publish with QoS = 1.
QoS% = 1
RMFV% = 0
MQTT "publish", Topic $, $ MessageSend $, QoS%, RMFV%
To be able to manage the communications, I would need to know if the server did its acknowledgment (PUBACK) for my PUBLISH before making another PUBLISH. In this way, I could know if the communication is good.
My RealtimeLog:
But, I do not know how to check if the PUBACK is received before doing another PUBLISH.
Thanks again
Christian
Hi Christian,
Sorry about that, I couldn’t quite find an MQTT solution at the time, so I was trying to give another solution that might work in the short term. Could you do a while loop to make it wait until it sees the string received PUBACK to send another Publish?
-Tim
Hi Tim,
Yes, this idea interests me 
Thanks
Christian
Hi Christian,
I heard from Simon that he is helping you work on some code. Can you let me know if the code he sent works for you?
-Tim
Hi! Could you share this code with me?
Thanks!
Hi Tim,
I’m going to test this week and I’ll get back to you with the result.
Thank you
Christian
T1:
ConnStatus% = MQTT "STATUS"
IF ConnStatus% = 5 THEN
counter% = counter% +1
SETSYS PRG,"RESUMENEXT",1
MQTT "PUBLISH", "/topic/flexy", "Hello From Flexy " + SerNum$, 0,0
PRINT "Message published to the MQTT broker " + STR$ counter%
ErrorReturned = GETSYS PRG,"LSTERR"
Print ErrorReturned
IF ErrorReturned=28 THEN
Print "ERROR PUBLISH"
ENDIF
ELSE
PRINT "Error : Flexy not connected"
ENDIF
END
Hi,
After several tests, here is the code I am currently using:
== Cyclic Section ==
@MQTTConnection()
// Your MQTT Publish here if (MQTTComOK% = 1)
== Init Section ==
MQTTComOK% = 0
@InitMQTTConnection()
== User Section ==
FUNCTION InitMQTTConnection()
FirstConnection% = 1
MQTT "close"
LastEtatWan% = @WANState%() //use in @MQTTConnection()
IF LastEtatWan% = 1 THEN
PRINT "WAN UP"
ELSE
PRINT "WAN DOWN"
ENDIF
ENDFN
FUNCTION WANState%()
SETSYS INF, "LOAD"
$IP$ = GETSYS INF, "VPNIP"
IF($IP$ = "0.0.0.0") THEN
$WANState% = 0
ELSE
$WANState% = 1
ENDIF
ENDFN
FUNCTION MQTTConnection()
$EtatWAN% = @WANState%()
IF (($EtatWAN% = 1) And (FirstConnection% = 1)) Then
@openMQTT_Azure()
ONMQTTSTATUS '@MQTT_StatusChange(MQTT("status"))'
MQTT "Connect"
FirstConnection% = 0
ENDIF
IF (($EtatWAN% = 1) And (LastEtatWan% = 0)) Then
PRINT "WAN is now up"
LastEtatWan% = 1
ENDIF
IF (($EtatWAN% = 0) And (LastEtatWan% = 1)) Then
PRINT "WAN is now down"
LastEtatWan% = 0
ENDIF
ENDFN
FUNCTION MQTT_StatusChange($status%)
IF $status% = 5 Then
MQTTComOK% = 1
PRINT "MQTT connected: "; $status%
ELSE
MQTTComOK% = 0
PRINT "MQTT disconnected:"; $status%
ENDIF
ENDFN
FUNCTION openMQTT_Azure()
IoTHub$ = "Your Hub"
DeviceID$ = "Your Device"
SASToken$ = "Your SASToken"
QoS% = 1 //Quality of Service Values
RMFV% = 0 //Retained Message Feature Values
MQTT "open", DeviceID$, IoTHub$+".azure-devices.net"
MQTT "setparam", "port", "8883"
MQTT "setparam", "keepalive", "30"
MQTT "setparam", "username", IoTHub$+".azure-devices.net"+"/"+DeviceID$+"/api-version=2017-11-11"
MQTT "setparam", "password", SASToken$
MQTT "setparam", "CAFile", "/usr/CA_Azure/BaltimoreCyberTrustRoot.pem"
MQTT "setparam", "CleanSession", "1"
MQTT "setparam", "ProtocolVersion", "3.1.1"
MQTT "setparam", "TLSVersion", "tlsv1.2"
MQTT "setparam", "log", "1"
MQTT "setparam", "MaxInFlight", "50"
PRINT 'MQTT:"open and setparam" with Azure'
ENDFN
With QoS = 1, my publish data is stored for 50 transactions.
Hi Christian,
Did you still have any questions for this, or are you all set with MQTT?
-Tim
It’s good for the moment.
I hope in a futur firmware can use the instruction MQTT “status” to follow the status of the MQTT connection. Problem also found by Simon.
Thanks again
Christian