HRW HPE-BNSMA V401 Manual 111201.doc E. & O. E. / Subject to change without notice
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Operation Overview
The gateway comprises two sections; the BACnet MS/TP device and the SMA network reading data
base.
BACnet Device
The gateway is BTL listed, conforming to the BACnet standard’s requirements for device & object
discovery and network communication initiations and responses.
During commissioning the following should be configured:
Node # (local network unique number)
Device Instance (system-wide unique number)
MS/TP network baud rate
Maximum Master (MM), set to the highest node number existing on the network, for limiting
network traffic to only those devices that exist on the network
Up to 250 AV objects relating to the SMA network devices’ data points being read,
AV4…AV253
SMA Network Gateway
250 device data points may be configured, from up to 32 SMA devices. Each data point constitutes a
BACnet object (AV).
It is important to have the SMA device manufacturer’s manual available to assist with SMA point
address settings although the gateway’s Diagnostic and Terminal functions mean the available data
points can be identified without the manufacturer’s manual if need be.
For each required SMA data point the gateway data base point configuration consists of:
1. SMA device address
2. Channel number of the point required to be read
3. Scaling Type selection for manipulation of the read raw data before passing to the BACnet side
4. Point Type selection for proper interpretation of the received raw data before further
manipulation
BACnet Priority Array
The BACnet protocol utilises a Priority Array for each object to enable various network devices to take
control of a device’s object based on the level of need. The priorities are in the range 1 (high priority) to
16 (Auto operation).
In respect of this device:
The point database objects are NULL priority, signified by ‘17’ when viewing the points in
engineering Terminal mode
Manually overriding a point value via terminal mode invokes priority level 9
Release of a manual results in an object reverting to NULL or next lowest and still valid priority
level if it has been commanded from another device in the system (such as the BMS)
For normal reading of the SMA network points should always be at NULL priority
