Is my meter fully supported?

Chances are that your meter is supported, providing that it is fully compliant with the EN13757 Mbus standard. The standard allows for manufacturer-specific data, which the driver may not support. Refer to the Meter Installation Notes for further information.

Why does the discovery process have two major operations?

The Mbus driver carries out a detection phase before the normal Niagara discovery phase because of the inherent delays an Mbus network requires. You manage these delays by adding Mbus slave meters to the network on a unit-by-unit basis.

For example, some slave units require at least 10 seconds between messages. After transmitting the initialisation message, the system follows up with an are-you-there message and two requests for data with differing FCB (Frame Count Bit) values. These messages can require over 40 seconds just for a single slave device.

A full primary address search for potentially 250 devices could take over two hours. The selective search offered by the Network Manager makes detection followed by discovery more manageable.

Why does Niagara not discover my device, but another software tool does?

Some Mbus devices do not fully support the Mbus standard (EN13757–3) default modulation rate of 300 baud.

Can I speed up the discovery process?

The time between messages and time-out periods are set to cater to the worst case meters tested by the software developers. You can use the Inter Message Delay and Response Time properties on the Mbus Network property sheet to speed up the process, typically down to five seconds.

How do I add a slave device to the network?

There are two ways to add slave devices:

If the device’s primary address is not unique, or if it has a value of zero (0), disconnect any already-connected devices, connect the device that needs a new primary address to the network as the only device on the network, right-click the Mbus network component in the Nav tree and click Actions > Assign Address. This action gives the device a valid and unique primary address.

Following the initial discovery, another discovery may be required after you add a device to the network. This is because some devices output a series of different messages, which require multiple requests. The Cycle Quantity property serves these devices. This property defines the number of commands required to obtain all message information. To access this property, select the meter device in the Discovered pane of the Mbus Device Manager view, then click the Edit button.

How do I verify the value to set for the Device Cycle Counter?

After adding a device to the network, import a history or do a point discovery, and check that all data you expect are present. In the point and history discovery windows, the Record Counter values identify the responses to the different commands.

Why can’t I discover my device after connecting it as the only device on the network?

Some devices require more time for initialisation and discovery. If you reduced the values for Inter Message Delay, Response Timeout and Initialisation Delay, set them back to their defaults (12 seconds) until you successfully add this device.

The system’s inability to discover a device is a limitation of the device, not the driver. Twelve (12) seconds may be insufficient for some devices.

Changing the baud rate on the device from 300 baud to a higher rate may speed discovery.

How unique is my parameter?

The Mbus driver uses the Units, Description, Orthogonal Description, and Record Number properties to identify a parameter. This identity must be unique unless the parameter is part of a data block or array. This identity also complies with the needs of the storage block, for example, length of block, start time, time interval, and position in block. The block cannot traverse message boundaries. All elements of the block must be in the same message and follow contiguously.

Why does the Relay MBSheet software read in data faster than this driver?

The Relay MBSheet does not fully comply with the Mbus standard. When tested, it did not seem to support continuation blocks. This means that it reads the first set of data only. The Niagara Mbus driver continues to read the continuation blocks until all are received. Thus, the Relay seems to complete the process fairly quickly.

Some meters require an inter-message interval. The Niagara Mbus driver supports these required intervals between continuation blocks, which can amount to several minutes before the system reads all data and updates the interface.