unreachable

Hir Sir/ Ma'am,

 

Please help me on this.

 

Yesterday, I experience difficulty on wireless.

 

All of my 5 field instrument installed became unreachable, and when I’m tried to connect the instruments again, 3-4 hours later the nearest transmitter (WDT-102) which is about 300-400 meters away from the gateway still not connecting to the network.

 

And when I put their spare transmitter between the gateway and WDT-102 it connects to the network even after I remove the spare transmitter.

What is the possible reason why its happen. And take note that there is Fog in that place.

 please see below for reference.

.

  • Hi Zar

    Please find below suggestion from our Wireless specialist :

    Rain/fog/moisture affects the ability of the device to capture a signal.

    Thus when the transmitter was all by himself the handshake between the GW and Transmitter is not getting completed.

    Once it is connected the GW will allocate a time/bandwidth for the transmitter after that it will try to check other paths.

    I would not remove the repeater just yet, I would try to check signal between transmitter and GW if it is above -75 RSSI and has 60% path stability.

    Are all the transmitters connected back to gateway now?

  • Zar,

     Do you have a plan view of your transmitter locations? It appears that all of your transmitters rely on a single connection back to the gateway. This is not ideal, as the loss of that single transmitter isolates the rest of the field. This may be unavoidable, however, by reviewing the plan view, you may be able to determine a more appropriate location for the gateway (or other repeaters).

    Regards

    Craig

    Craig Abbott - Wireless Specialist (South Eastern Australia)

  • In reply to Emmy Lim:

    Hi Emmy,

    Yes, Its already connected again, but my worry is what if it happens again? what will be your suggestion?

    thank you.

  • In reply to Craig Abbott:

    Hi Craig,

    Thank you for that information.

  • Zar,
     
    Have you evaluated this network using the AMS Wireless Snap-on?
     
    It seems as though you have a pinch-point (WDT-102) that also has poor RSSI to the Gateway.
     
    Regards,
     
    Douglas Hoerning  Wireless/Plantweb Specialist  Rosemount Measurement
    Emerson Process Management 8200 Market Blvd. Chanhassen MN 55317 USA
    T +1 952 906 8625 Email: Doug.Hoerning@Emerson.com
     
     
     
     
    From: zar [mailto:bounce-zar@community.emerson.com]
    Sent: Wednesday, October 16, 2013 8:57 PM
    To: Wireless@community.emerson.com
    Subject: [EE365 Wireless Track] unreachable
     

    Hir Sir/ Ma'am,

     

    Please help me on this.

     

    Yesterday, I experience difficulty on wireless.

     

    All of my 5 field instrument installed became unreachable, and when I’m tried to connect the instruments again, 3-4 hours later the nearest transmitter (WDT-102) which is about 300-400 meters away from the gateway still not connecting to the network.

     

    And when I put their spare transmitter between the gateway and WDT-102 it connects to the network even after I remove the spare transmitter.

    What is the possible reason why its happen. And take note that there is Fog in that place.

     please see below for reference.

    .

  • In reply to Douglas Hoerning:

    Hi Sir Douglas,

    The last time I check the Statusof the RSSI of WDT-102 is -81db. I don't have any AMS Wireless Snap-on as of now.

    Thank you.

    Regards,

    zar

  • Zar,
     
    -81dB is not a reliable connection.  They really need to be -75dB or better.
     
    Doug
     
    From: zar [mailto:bounce-zar@community.emerson.com]
    Sent: Sunday, October 20, 2013 8:16 PM
    To: Wireless@community.emerson.com
    Subject: RE: [EE365 Wireless Track] unreachable
     

    Hi Sir Douglas,

    The last time I check the Statusof the RSSI of WDT-102 is -81db. I don't have any AMS Wireless Snap-on as of now.

    Thank you.

    Regards,

    zar