Your MUST inverter in the app, over an RS-485 cable
The ED-1.1 gateway plugs into the inverter's "RS-485, CAN" port and reads it directly: solar, battery, grid and household load. From the app you can change priorities, charge currents and battery voltages, and schedule charging from the grid.
We are connecting the first MUST stations now. The app: from $2 a month.
Connecting the first stations
We built MUST support from the manufacturer's documentation, and we are connecting the first stations now. If you own a MUST, write to us on Telegram: we will help with the cable and stay with you until your station shows up in the app.
How to connect: three wires, not a network cable
The inverter's port is labelled "RS-485, CAN". Besides RS-485 it carries the CAN lines to the battery, and the ED-1.1 socket has its own power supply on the neighbouring pins. So a MUST cable has three wires only: pins 1, 2 and 3 connect one to one, and the rest stay unconnected.
| Pin | MUST "RS-485, CAN" | ED-1.1 | In the cable |
|---|---|---|---|
| 1 | B | B− | yes |
| 2 | A | A+ | yes |
| 3 | Ground | Ground | yes |
| 4 | Ground | Power, negative | no |
| 5 | CAN-L | Power, positive | no |
| 6 | CAN-H | Ground | no |
| 7 | — | A+ | no |
| 8 | — | B− | no |
Never connect a MUST to the ED-1.1 with an ordinary network cable. That cable connects all eight pins: the gateway's power supply reaches the inverter's CAN lines, and the inverter loses its CAN link to the battery.
Pins are numbered with the contacts facing you and the latch down, pin 1 on the left. Go by pin number, not by wire colour. If the inverter does not answer, swap A and B: that does no harm.
What Svitgrid reads
Solar
Solar panel power and voltage. On the PV1900, each panel input separately.
Battery
Voltage, current, and charge and discharge power.
Grid and home
Grid voltage and frequency, power from the grid, and household load.
Temperature
The inverter temperature.
Battery charge in percent
The PV1900 passes it on from the battery's BMS when the battery is linked to the inverter. The PV1800 and PH1800 do not report a percentage, so the app estimates the charge itself.
What you can control
Output priority
Where the inverter powers the house from first: solar, battery or grid.
Charger priority
What charges the battery: solar only, solar and grid, or solar first.
Charge currents
The charge current from the grid, from solar, and the overall maximum.
Battery voltages
The voltage at which the inverter stops discharging, and the one at which it stops charging. Not every inverter firmware has these settings.
Calendar
Charge the battery from the grid at the hours you choose, at the current you choose, or run on the battery. When the event ends, the inverter goes back to your settings.
Rules
For example, change the stop-discharge and stop-charge voltages while a rule holds, then restore yours.
Control works when the ED-1.1 reads the inverter over the cable.
Getting connected
ED-1.1 gateway over the cable
- Take out the MUST Wi-Fi stick if one is plugged in.
- Connect the inverter's "RS-485, CAN" port to the ED-1.1 with a three-wire cable: pins 1, 2 and 3.
- Power the gateway and add it in the app.
- The gateway finds the inverter on the cable by itself.
MUST Wi-Fi stick
- Support for the MUST Wi-Fi stick is in development.
One poller at a time: while the ED-1.1 reads the inverter, the MUST Wi-Fi stick must not poll it as well. More about the gateway on the ED-1.1 page.
MUST models the ED-1.1 works with
| Model | Type | Phases | Available |
|---|---|---|---|
| PV18-1012 VPM / VPM II / VPK | Hybrid · 1 kW, 12 V | 1 | Data + control |
| PV18-1512 VPM | Hybrid · 1.5 kW, 12 V | 1 | Data + control |
| PV18-2012 ECO / PRO | Hybrid · 2 kW, 12 V | 1 | Data + control |
| PV18-3024 VPM / VPK / PRO / VHM | Hybrid · 3 kW, 24 V | 1 | Data + control |
| PV18-3224 VPM / VPM II / PRO | Hybrid · 3.2 kW, 24 V | 1 | Data + control |
| PV18-3524 PRO / ECO | Hybrid · 3.5 kW, 24 V | 1 | Data + control |
| PV18-3624 PREM | Hybrid · 3.6 kW, 24 V | 1 | Data + control |
| PV18-4024 ECO | Hybrid · 4 kW, 24 V | 1 | Data + control |
| PV18-5048 VHM | Hybrid · 5 kW, 48 V | 1 | Data + control |
| PV18-5248 PRO | Hybrid · 5.2 kW, 48 V | 1 | Data + control |
| PV18-6048 PRO II | Hybrid · 6 kW, 48 V | 1 | Data + control |
| PH18-5248 PRO | Hybrid · 5.2 kW, 48 V | 1 | Data + control |
| PV19-4024 EXP | Hybrid · 4 kW, 24 V | 1 | Data + control |
| PV19-6048 EXP | Hybrid · 6.2 kW, 48 V | 1 | Data + control |
The PV1800 (PV18 VPM, VPM II, PRO, ECO, PREM, VHM), PH1800 (PH18 PRO) and PV1900 (PV19 EXP) families. The app suggests the model from what the inverter reports about itself. Another MUST model? Write to us on Telegram.
Questions from MUST owners
Can I use an ordinary network cable?
No. It connects all eight pins, so the gateway's power supply reaches the inverter's CAN lines and the inverter loses its CAN link to the battery. Use a cable with three wires only: pins 1, 2 and 3.
Can I keep the MUST Wi-Fi stick and add the ED-1.1 next to it?
No. The inverter answers one poller at a time, so the Wi-Fi stick must be out while the ED-1.1 reads the inverter.
Does Svitgrid work through the MUST Wi-Fi stick?
Support for the MUST Wi-Fi stick is in development.
Why does the app not show the battery percentage from the inverter?
The PV1800 and PH1800 do not report one, so the app estimates the charge itself. The PV1900 passes on the percentage from the BMS when the battery is linked to the inverter.
The app does not find the inverter on the cable. What now?
Most often A and B are swapped. Swap the wires on pins 1 and 2, check the ground on pin 3, make sure the MUST Wi-Fi stick is out, and search again.
Do I need an installer?
No. The cable goes into the inverter's "RS-485, CAN" port and into the gateway's socket, and setup takes a few minutes in the app.
Read next
Your MUST in the app
Order an ED-1.1, connect it to the "RS-485, CAN" port with a three-wire cable, and the gateway finds the inverter by itself. We are connecting the first MUST stations together with their owners.