[geoffers]

Aha - this is not a problem report, as I'm not really bothered with my IHD (since EOn can't update my meter with the correct tariff rates)... so this is more just a real-time observation, which may be of use to anyone else with IHD connection issues.

My IHD has been connected for maybe 4 years without me being aware of any issues.

However out of the corner of my eye I suddenly saw the 3 LEDs at the bottom (green orange red) flash up; it goes through its boot up process; then sits there with the top-left wireless connection symbol flashing saying "waiting for current data"

Then it goes back through this process every few minutes.

I checked the green lights on the meter hub, and suspiciously the WAN light is not flashing (the others SW; HAN; GAS are flashing as normal - MESH never flashes so that's normal too)

So it looks like (in my case at least) the lack of IHD connection is nothing to with it being able to connect to the hub or not (via the HAN), but looks more like it must be due to the WAN connection via 02 to the DCC which has dropped? Possibly?

[retrotecchie]

@geoffers

HAN and WAN are two completely separate functional processes in the Comms Hub. One does not depend on the other for anything. Datawise, the two are also completely isolated from each other, for the obvious reasons.

HAN has read only access to a very limited number of registers in the meter itself. It can read consumption figures, date and time, meter serial numbers and tariff registers but that is all. The IHD cannot send anything to the meter, again for obvious reasons.

The WAN can set registers in the meter itself through SMETS command messages from the DCC but cannot directly send anything to the IHD. A WAN dropout should not have any bearing on IHD functionality. This is designed into the specification.

[geoffers]

@geoffers

Aha +1 indeed - IHD is back up again, and guess what ...the WAN light is flashing again.

So the IHD connection issue is clearly a WAN connection problem, and nothing to do with the IHD connecting to the home-area-network

I rest my case m'lud 🤓

[geoffers]

Originally Posted by retrotecchie

@geoffers

HAN and WAN are two completely separate functional processes in the Comms Hub.
.

Yes, I know that...

The point is that the WAN dropping out caused the IHD to appear to fail to connect

When the WAN connection came back up the IHD came back OK too

Might not be what the specification suggests, but it's what I just observed in real time...

[retrotecchie]

@geoffers

Very interesting. But completely contra to what the comms hub technical specifications state.

Having finally got the official documentation on the 20 pin ICI (the connector that docks the hub to the electricity meter) plus full specifications of the SKU hub internals the only way I can see that WAN can affect HAN operation is via a couple of more obscure SMETS commands which can remotely issue a reset command to the HAN. It may be that this is what happened here. Until the WAN reconnects, then the meter doesn't see the command to reconnect the HAN. But the commands operate on a physical register in the actual meter, not directly across the two wireless communications interfaces.

But that's just from the Gospel according to Toshiba.

Bottom line is, it's working again. But has it updated your tariff...that's the $64000 question!

[geoffers]

Originally Posted by retrotecchie

@geoffers

Very interesting. But completely contra to what the comms hub technical specifications state.

Having finally got the official documentation on the 20 pin ICI (the connector that docks the hub to the electricity meter) plus full specifications of the SKU hub internals the only way I can see that WAN can affect HAN operation is via a couple of more obscure SMETS commands which can remotely issue a reset command to the HAN. It may be that this is what happened here. Until the WAN reconnects, then the meter doesn't see the command to reconnect the HAN. But the commands operate on a physical register in the actual meter, not directly across the two wireless communications interfaces.

But that's just from the Gospel according to Toshiba.

Bottom line is, it's working again. But has it updated your tariff...that's the $64000 question!

Section 4.3 of the Comms Hub spec states this...

4.3 Physical Requirements
A CH shall as a minimum include the following components:
i. a Clock;
ii. a Data Store;
iii. a HAN Interface;
iv. a Random Number Generator;
v. a WAN Interface; and
vi. an Intimate Physical Interface.

So seeing that the CH maintains both the HAN and the WAN interfaces, I can see no reason why if the CH detected that it has lost WAN connection it shouldn't be programmed to instruct the IHD to go through a reboot process until everything is hunky-dory again

[retrotecchie]

@geoffers

Perhaps, but all my neigbours IHDs seem to carry on displaying consumption despite there being no WAN connection in the village for the last year. No WAN hasn't disabled anyone's HAN. Maybe it's specific to particular hub/ meter combinations?

[meldrewreborn]

@retrotecchie

I agree. The IHD gets its data from the meter via the communication hub over the HAN. That data may not be correct in terms of pricing but it doesn’t need the WAN to function.

if the WAN is not functioning then the correct pricing data can’t be put onto the meter, so after a relatively short period ( max 3 months) the pricing data will be wrong for most customers on variable tariffs - those on fixed tariffs will stay correct until their tariff expires.