Wireless Cold Water Meter M-ETH W3M Q3:2.5 DN15 don’t respond to wake up

[joaopedrotaveira]

Hi there,

Thank you for your work.

I’ve been trying to setup parameters of a Wireless Cold Water Meter M-ETH W3M Q3:2.5 DN15 but I get no response.

I already have some opto link assembled by my self and they work ok with DLMS/COSEM meters. Does M-Bus have a different spec about opto link? My adapters worked well with Iskra meters.

What can I doing wrong?

My meter is this one:

Thank you very much in advance.

Best Regards,
João Pedro Taveira

[scyllaL]

I have the exact same issue and same water meter. This is the output I see in terminal.

Setting serial port to 2400 baud 8N1 Sending wakeup bytes UART>025> 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 [...] UART>025> 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 Setting serial port to 2400 baud 8E1 Getting device parameters MBUS_C: 0x53 MBUS_ADR: 254 MBUS_CI: 0x51 UART>014> 68 08 08 68 53 fe 51 0f 04 00 00 60 15 16 UART<064< 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 M-Bus long frame: Invalid start header M-Bus protocol error, received 64 unprocessable bytes.

[joaopedrotaveira]

@scyllaL that you are receiving might be echo of the wakeup frames. Usually the UART ports might have buffers in the device or on OS side, which captures everything they receive, even before you do a read to the port.

Try to move away the sensor a little bit from the watermeter. You can also try to figure out the distance you don’t get echo by using a program that talks with your sensor, like CoolTerm. Any key you type on keyboard might be echoed to the terminal. Move the sensor away from the meter until o don’t get echo.

My problem is that I can’t see any feedback from the meter. Using a smartphone camera, the sensor IR-led blinks but the meter doesn’t sends any data, that would eventually me mixed with the echo, but no. I can’t get any feedback from my meter.

@scyllaL if your meter shows activity in the camera when you try to send data but receive echo, there might be hope.

[scyllaL]

@joaopedrotaveira I already tried to get some blinking activity from the IR Module, however I do not get any from the watermeter. For the IR Module connected to my computer, it blinks.

Do you know whether the IR Module in the WaterMeter is also only active during wm-bus activity hours?

[joaopedrotaveira]

@scyllaL I have now idea if the watermeter is only active during wm-bus activity. I would make no sense. The wake up process is suposed to wake up the device no matter the activity hours.

[scyllaL]

So I tried many times now, it seems that the result "55 55 55..." comes every time something is in front of the opto head. If there is nothing just in front of the IR module, it waits some time but the results do not make any sense.

I cannot see any IR activity in my water meter. I now purchased another one, just to ensure that there is no issue. Might it be the case, that another wake up sequence is required?

@ joaopedrotaveira Which firmware is running on your whatermeter? Mine is F105-105

[hn]

@joaopedrotaveira, sorry I can't really help you out. I'm neither an M-Bus expert nor do I have access to other water meters. I built the software and hardware specifically for my device, and that's exactly how it works for me.

@scyllaL The 55's are the IR echo. I moved my "2€ optical head" and adjusted the angle, and eventually it worked.

[scyllaL]

May I ask what type of computer you are using? I tried on a mac and moved to a raspi, just to make sure it's not the computer.

I put some cardboard in between the two diods, which at least helped to get rid of all the 55's... do you put the IR diodes right against the clear housing, or do you have some distance between optical head and watermeter?

[hn]

@scyllaL I think I used various laptops and a Pi as well, that made no difference. The RX-Diode is covered with duct tape to eliminate echo. And I pressed both diodes directly to the watermeter housing with two fingers (no distance).

[joaopedrotaveira]

I will try to create a serial port in half-duplex mode using a arduino atmega328p... It might work.

update: no. it doesn’t work.

[patiii]

I have the same meter and the same problem.
I’ve tried two different optical heads and various hardware—all to no success.

I couldn’t get any response from the meter—no matter how I oriented it. It seems the meter isn’t even transmitting anything—at least I don’t see an IR signal with the camera.

The optical sensor is transmitting signals (according to my cell phone camera) and either receives nothing in return or an echo of the wake-up request.

Has anyone successfully read data from this meter yet? If so, what hardware did you use?

[joaopedrotaveira]

Could be possible that this device requires some special (un-common) wave length led that we aren’t using, but fortunately @hn have it?

[hn]

My order list shows "5pcs/lot SFH309FA SFH309F SFH309 DIP-2" , "F3mm 850nm, 10pcs" and "F3mm 940nm, 10pcs" for the rx/tx diodes. I don't remember which ones I actually used.

Side note: for reading the watermeter, this might be an option.

[patiii]

So it's probably the hardware's fault that it's not working.
In other words, the meter doesn't need a special wake-up signal—just the right diodes.

I don't want to read the meter via infrared at all—I'm already using a CC1101 on the ESP for that.
My concern is setting the transmission times; unfortunately, the meter only transmits between 8 a.m. and 6 p.m.

[joaopedrotaveira]

thanks for the details @hn

I think that everybody wants the same, meter to transmit every time.

[hn]

Well, my water meter is a “DWZ02” series one, and yours is from the "W3M" series. I have no idea if they are configured the same way or not.