mbus: M-Bus

M-Bus is a series of European standards for remote reading of water, gas, and electricity meters (EN 13757).

This API has support for two different types of M-Bus: Wired M-Bus and Wireless M-Bus.

Wired M-Bus uses two wires to communicate with a number of devices that might be powered by the master.

The master sends a request and the slave devices respond.

The slave devices can be addressed using either a short primary address which is an integer typically in the range 1-250, or the secondary address which is a unique 16-byte string. See mbusScan for details about the format of the secondary address.

Wireless M-Bus uses RF to transmit the messages.

The slaves send data periodically without the master needing to do anything.

Wireless M-Bus only uses secondary addresses.

Wireless M-Bus data is often encrypted, so the correct decryption key is needed to parse the data.

When a Wireless M-Bus frame is received, it is kept in an internal buffer until it is either read with mbusRecordSlaveInfo or mbusReceive or it is overwritten by a newer message when the buffer is full.

The following functions are used to access both types of M-Bus:

	•mbusOpen	Opens a connection to an M-Bus interface,
	•mbusClose	Closes an M-Bus connection.
	•mbusRecordSlaveInfo	Get information about slave device.
	•mbusRecordCount	Get number of records on slave device.
	•mbusRecordGetInfo	Get information about a record.
	•mbusRecordGetType	Get record data type.
	•mbusRecordGetBuffer	Read record value into a buffer.
	•mbusRecordGetInt	Read record value as a DINT.
	•mbusRecordGetIntLarge	Read large record value as two DINTs
	•mbusRecordGetFloat	Read record value as a float.
	•mbusRecordGetString	Read record value as a string.
	•mbusRecordGetLinsec	Read record value as a linsec value.
	•mbusSend	Send a raw M-Bus frame.
	•mbusReceive	Receive a raw M-Bus frame.

The following functions are only used for wired M-Bus:

	•mbusBaudSet	Change the baud rate for an M-Bus connection.
	•mbusScan	Scan for M-bus slave devices.
	•mbusScanStop	Stop the M-Bus scan.
	•mbusSlaveConfigBaud	Change baud rate on slave device.
	•mbusSlaveConfigAddress	Change primary address on slave device.
	•mbusSlaveConfigReset	Send application reset to slave device.
	•mbusDataRequest	Request data from slave device.
	•mbusSelectSecondary	Select a secondary address to be made available as primary address 253, for use with mbusSend.

The following functions are only used for wireless M-Bus:

	•mbusSlaveRegister	Register a wireless M-Bus slave device with optional decryption key.
	•mbusSlaveUnregister	Remove registration.
	•mbusFilterEnable	Control if data from all or only registered slaves should be received.
	•mbusDataReceive	Receive a frame from wireless M-Bus
	•mbusSetSenderAddress	Set address to use as sender when sending Wireless M-Bus frames with mbusSend.