Replacing a smart meter comms hub

Reed_Richards

So @Qyburn sees a cache with today's date whilst @Ildhund has a cache from 1st August (19 days ago).  That's quite s disparity; I wonder if it has any significance?

Reed_Richards

A quick sanity check.  My HAN light is solid green.  Will it start to flash once every 5 seconds if my comms hub is successfully commissioned or is it not flashing because there are no devices associated with it? 

When my original comms hub was installed it did not complete commissioning until after the installer had left so I didn't get an IHD for some months.  I have a picture taken shortly after installation which appears to show that the HAN light was off, which must mean that it was flashing.  If so, then a flashing HAN light is an indicator of a commissioned hub; can anyone confirm this?  

Ildhund

All is revealed in Appendix B on p. 19 in this DCC doc: communications-hub-supporting-information-v20.pdf. "HAN initialised, no HAN devices in CHF Device Log". So I'd say yes, "... not flashing because there are no devices associated with it." 

Reed_Richards

Yes, I agree that is what the book says, but I went from August to November 2023 with no devices on my HAN.  I don't recall the light being solid green then and then one photograph I can find from that time suggests that it wasn't.

On the other hand I can find a post from someone who claims to work in the industry:

WAN flashing every 5 suggests it's established a connection
Solid HAN light means the meter has not connected to that comms hub

    

QrizB

Reed_Richards said:

Yes, I agree that is what the book says, but I went from August to November 2023 with no devices on my HAN.

The HAN isn't just for the IHD. Your electricity meter also connects to the hub via the HAN. (If you had a gas meter, that's also HAN connected.)

It might seem odd to use the HAN when there's a physical connection between the electricity meter and the comms hub, but I guess this allows for rare situations where the comms hub is remote.

Reed_Richards

So as per the quote I gave above, the solid HAN light means that the meter is not connected to the hub.

Presumably during the commissioning process, contact is made with the comms hub and it is instructed to connect to the meter.  But this must have failed, despite the fact that the WAN light is indicating a comms signal (by flashing once every 5 seconds).

@QrizB I don't see that you could ever have a comms hub that is fully remote from the meter because only if it is powered by a connection to the meter could you be prevented from switching it off.  In the north (Arqiva LRR) you can get a comms hub with a flying lead and my installer tried one but it was only about 50 cm long and too short to move the comms hub a significant distance away.

QrizB

Reed_Richards said:

QrizB I don't see that you could ever have a comms hub that is fully remote from the meter because only if it is powered by a connection to the meter could you be prevented from switching it off.

I'm sure we've seen (sometime in the past five years) a comms hub fitted without a smart electricity meter, but with a smart gas meter. The hub was powered separately.

Reed_Richards

When the installer came, he did not seem to have any means of determining the comms signal strength, unless he left it in the van.  If you could do that with a hand-held device and then position the comms hub to suit it might make a significant difference connecting smart meters in areas where the signal is weak.

Is there such a device, a hand-held signal strength meter that I could tune to 420 MHz?  Perhaps some sort of Spectrum Analyser (with an aerial)?  There is also something called a Vector Network Analyser; I'm not sure how that differs from a Spectrum Analyser.       

debitcardmayhem

The HAN uses Zigbee surely , 2.4Ghz.  Have you spokento you supplier, are they or even Bright or Loop seeing data from your meter? If a dual comms hubalso 868 Hz

Reed_Richards

Yes indeed, the HAN uses Zigbee (it's written on the hub).  But in order to connect the comms hub to the meter (which I have now learned is via the HAN) the comms hub needs to receive and obey the necessary command.  This comes (in my case) by LRR at 420 MHz (420 is written on the comms hub).  And this hasn't happened, despite the fact that the comms hub indicates that it has a signal.  Since the comms hub isn't talking to the meter, nobody can see the meter data.