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Run these checks when the gateway is Online and the Modbus devices are added. Otherwise you only notice a wrong value or an alert without a recipient at the first fault. If the gateway still shows Pending, first follow Gateway does not come online.
What you need
- The role Owner, Admin or Technician.
- The display of each Modbus device, or a value that you measure on site.
- A computer with a large screen for Export configuration.
Compare values with the display
A value that the Modbus device shows itself is the quickest check of address, data type, byte order and scale. The live values refresh with every reading, as described in View values and charts.
Open the gateway list
Open Gateways in the menu.
Open the gateway
Click the gateway. The gateway page opens on the Overview tab, with one card per Modbus device.
Open the Modbus device
Click the card of a Modbus device. The table shows the Laatste waarde (last value) for each register.
Compare the values
Compare two or three values from the display with the Laatste waarde. Choose values that are not 0. A register that is 0 also shows 0 with a wrong byte order.
Repeat this for each Modbus device. The table shows what a deviation usually comes from.
| What you see | Usually |
|---|---|
| An impossible number, such as millions of volts | Byte-volgorde (byte order) of a 32-bit value |
| The digits are right, but the decimal point is in the wrong place | Schaal (x) (scale). The portal shows the value read times the scale |
| Always 0, while the display shows something else | Byte-volgorde of a float32, or Datatype (data type) |
How to adjust a register is described in Values are wrong.
Check the monitoring
A gateway that you link with Add gateway immediately gets the alert rule Gateway offline and the five checks of automatic monitoring. An existing gateway without default alerts never gets them by itself.
Open the gateway
Open the gateway.
Open the settings
Click the pencil at the top right (Gateway settings).
Read the monitoring
Scroll to Automatic monitoring. Under the heading you see how many checks are on, in trial run and off. If the default alerts have been applied, the date appears below it.
If there is no date, add the default alerts with Apply default monitoring, as described in Automatic monitoring. The checks then start in trial run by default. Gateway offline turns on immediately.
Check the connection
In the block Uitlezen via de SIM (reading via the SIM), Gateway settings shows whether the gateway now sends over the cable or over 4G. Next to Verstuurt nu via (sending now via) you see Kabel (cable) or SIM, followed by the date and time when that connection started.
If the gateway is connected to the network on site, it should show Kabel. If it shows SIM while the network cable is plugged in, the gateway does not reach the internet over the cable and sends over 4G. On the SIM it reads out no more often than the SIM interval, by default 300 seconds, and that traffic uses 4G data. What the network must allow is described in Network requirements for the gateway.
If it shows Onbekend (unknown), the gateway runs older software that does not report its connection. It then reads out no more often than every 60 seconds, also over the cable. The SIM interval and the other settings are described in Gateway settings.
Check the alert email recipients
The default alerts have no email addresses of their own. Their email goes to the recipients in the block Who gets emails for alarms on the gateway page.
Open the gateway
Open the gateway.
Find the block
Scroll to Who gets emails for alarms at the bottom of the page.
Check the recipients
Check that there is at least one recipient. That is a name with the switch on, a separate address or an address with Via the notification settings of the organisation.
If there is no recipient, no email goes out when an alert fires. The alert then appears only in the portal. A name with Will not receive it: alarm email is switched off in their own profile. does not count.
Turn on the switch next to your own name, or add a separate address as described in Choose who receives alert emails. Only an owner or admin adds a separate address. If your customer should receive alert email too, add their email address the same way.
Record the settings
Record in the handover file how each Modbus device is connected. The table shows where you find each item in the portal.
| Item | Where |
|---|---|
| Slave-adres (slave address) or Unit-ID, and for Modbus TCP the IP-adres (IP address) and the Poort (port) | Page of the Modbus device, block Verbinding (connection) below the registers |
| Uitleesinterval (seconden) (polling interval in seconds) per Modbus device | Page of the Modbus device, block Verbinding |
| Baudrate, Pariteit (parity), Stopbits (stop bits) and Databits (data bits) | Gateway settings, block Modbus RTU-bus (Modbus RTU bus) |
| Uitleesinterval via de SIM (seconden) (polling interval via the SIM in seconds) | Gateway settings, block Uitlezen via de SIM |
| Serial number | Header of the gateway page, below the name |
Export configuration puts the Modbus devices, the registers and the alert rules of the gateway in one JSON file.
Open the gateway
Open the gateway on a computer.
Open the menu
Open the menu with the three dots at the top right.
Export the configuration
Choose Export configuration. The browser downloads a file with the serial number in its name, such as
1234567890-config.json.
A complete list for the file, from address plan to topology drawing, is in the course lesson Modbus commissioning checklist and cheat sheet.
Let your customer view the installation
A public link to a dashboard lets your customer view the installation without an account. How to create that link is described in Share a dashboard with a link.
Updated on 7 October 2026
Still stuck?
Email or call us. Include the serial number of the gateway, so we can take a look straight away.
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