Configure the Wireless M-Bus Connector

Configure the Wireless M-Bus Connector to receive meter telegrams, add encrypted meters, and use automatically generated instances and items.

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Use the Wireless M-Bus Connector to receive data from compatible wireless meters through a supported USB receiver. The Connector listens for meter telegrams and automatically creates the corresponding instances and items in the Edge Portal.

The Wireless M-Bus Connector is receive-only. It does not write values or send commands to meters.

Before you begin

Make sure that:

You have permission to install and configure Connectors, instances, and items.
A supported Wireless M-Bus USB receiver is connected to SIA Connect.
The wireless meter is active and within reception range.
You know the meter encryption key if its telegrams are encrypted.
You know approximately how often the meter transmits. A meter must send a telegram before it appears in the Edge Portal.

Treat meter encryption keys as sensitive information. Store and share them according to your organization's security requirements.

Supported Wireless M-Bus receivers

Receiver	Connection settings used by the Connector	Connector behavior
Adeunis RF or AMR Wireless M-Bus USB receiver	115200 baud, 8 data bits, no parity, 1 stop bit	The Connector opens the receiver and listens for telegrams.
Amber AMB8665	9600 baud, 8 data bits, no parity, 1 stop bit	The Connector enables signal-strength information and configures C2/T2 receive-only mode.
IMST Wireless M-Bus receiver	57600 baud, 8 data bits, no parity, 1 stop bit	The Connector configures C/T mode and listens for telegrams.

The Connector identifies compatible receivers by their USB vendor and product identifiers. Unsupported serial devices are ignored.

How meter discovery works

The Wireless M-Bus Connector does not use the Discover instances or Discover items buttons. It listens continuously for valid telegrams from supported meters.

When the Connector receives a valid telegram from a supported meter, it:

Uses the meter serial number as the instance address.
Creates an instance if the meter has not been detected before.
Creates items for the data records contained in a successfully decoded telegram.
Adds a Signal strength item with the unit dBm.
Updates the items when subsequent telegrams arrive.

Instances and items are event-based because values arrive when the meter transmits. There is no polling interval to configure.

Set up the Wireless M-Bus Connector

Connect a supported Wireless M-Bus USB receiver to SIA Connect.
In the Edge Portal, go to Configuration > Connectors.
Install the W-MBus Connector if it is not already installed.
Enable the Connector.
Wait for the meter to transmit a telegram.
Go to Workspace > Instances.
Open the automatically created instance for the meter.

The generated instance name includes the meter manufacturer, serial number, device type, and the word Wireless.

Do not change the automatically assigned instance address. The Connector uses the meter serial number as the unique device identifier.

Configure an encrypted meter

If the meter sends encrypted telegrams, the instance reports Please provide encryption key until a valid key is configured.

Open the automatically created meter instance.
Select the option to edit the instance.
Enter the meter key in the Encryption key field.
Save the instance.
Wait for the meter to send another telegram.

Enter a 128-bit AES key as exactly 32 hexadecimal characters. For example, a valid key contains only the characters 0-9 and A-F and does not include spaces or a 0x prefix.

The current Connector supports unencrypted telegrams, AES-CBC mode 5, and AES-CTR Extended Link Layer mode 1. Other encryption schemes are rejected.

Enable and use the generated items

Items are created automatically after the Connector successfully decodes a telegram. Each generated item is:

Read-only
Event-based
Initially disabled
Identified by a generated unique record identifier
Assigned the name and unit reported by the meter telegram when available

Open the meter instance.
Open the Items section.
Review the automatically generated items.
Enable the items that you want to use.
Wait for the next meter telegram and confirm that the values update.

The Signal strength item reports the received signal strength in dBm. A value closer to zero normally indicates a stronger received signal.

Verify the setup

Confirm that:

The W-MBus Connector is enabled and does not report an error.
An instance appears after the meter transmits.
The instance address matches the meter serial number.
Items appear after a telegram is successfully decoded.
The required items are enabled and update when new telegrams arrive.
The Signal strength item shows a plausible value.

Understand telegram processing

Only meters with a supported medium type are added. Telegrams with an unknown medium are skipped.
Received telegrams that remain unprocessed for more than 60 seconds are discarded.
A compact telegram can require information from an earlier full telegram. The Connector cannot decode it until the corresponding full frame has been received.
A telegram with an invalid length, checksum, frame type, or encryption result is not used to create or update items.

Troubleshoot the Wireless M-Bus Connector

Message or symptom	Cause	Action
No known W-MBus dongles found	No supported receiver was detected.	Connect a supported receiver directly to SIA Connect, check the USB connection, and restart or re-enable the Connector. Confirm that the receiver model is listed in this guide.
The meter instance does not appear	No valid telegram has been received, the meter is out of range, or its medium type is unsupported.	Confirm that the meter is transmitting, move the receiver closer, reduce radio obstructions, and wait for the meter's next transmission. Review the system logs for rejected frames.
Please provide encryption key	The meter telegram is encrypted and the instance has no key.	Edit the meter instance, enter its 32-character hexadecimal AES key, save the change, and wait for the next telegram.
Decryption failed. Check the encryption key!	The configured key does not match the meter.	Confirm the key with the meter supplier. Enter exactly 32 hexadecimal characters without spaces or a prefix.
Invalid encryption key length	The key is not 128 bits long.	Enter exactly 32 hexadecimal characters, which represents 16 bytes or 128 bits.
Unsupported encryption mode, Unsupported encryption type, or Unsupported encryption scheme	The meter uses encryption that the current Connector cannot decode.	Check the meter configuration. Use unencrypted transmission, AES-CBC mode 5, or AES-CTR Extended Link Layer mode 1 where supported by the meter.
No previous full frame received or Compact DIFs array is empty	A compact frame arrived before the Connector had received the required full frame.	Keep the Connector running and wait for the meter to transmit a full frame. Check the meter transmission configuration if the error continues.
Checksum didn't match or Length didn't match	The received telegram is incomplete or invalid.	Check signal strength, receiver placement, radio interference, and the receiver connection. Wait for another telegram and review the system logs.
The instance exists but no items appear	The telegram could not be decoded, an encryption key is missing or incorrect, or the meter has not sent a valid data frame.	Check the instance error, configure the correct encryption key if required, and wait for another full telegram. Review the system logs for parsing errors.
Item values do not update	The meter has not transmitted again, the item is disabled, or reception is unreliable.	Enable the required item, check the meter transmission interval, and use the signal-strength value to assess reception.

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