Once you have connected to the device to be configured (see startup), this is the area of the dialog box where you will do most of the gateway configuration. Each "object" maps a LonWorks network variable to a BACnet object. The objects in Babel Buster 485XL are numbered 1 through 155, and include the AI, AV, BI, and BV objects.
Object: Enter a number 1 to 155 or scroll up and down. This object number is really a map number, and will translate into a different BACnet object number once you get past the AI objects.
Object Name: As you scroll through the maps, this window will show the actual BACnet object name and number.
Node: Indicates which of the 20 LonWorks devices in the gateway's device table this object will map to.
NV Index: Network variable index 0..61 selects which of the 62 variables in the LonWorks device this object maps to. This index is determined by the device manufacturer and is generally found in the XIF file or manufacturer's documentation. (More than the standard 62 network variables are not supported at this time.)
NV Type: The Standard Network Variable Type is indicated here. The type is found in the XIF file or device manufacturer's documentation. Refer to XIF to XML conversion instructions for short cuts on importing the XIF information. (Note: You can download a pdf file containing a complete definition of all network variable types at www.lonmark.org. You WILL need this document to do anything more than the default mapping created for you by xif2csv.exe. Due to copyright restrictions, we cannot provide it for you.)
Enable Map: Check this box to "turn on" this map. If not checked, the rest of the information in the map will be disregarded by the gateway, and in fact, the tool will only transmit the Enable flag to the gateway when you write this map if this box is unchecked.
Group: Check this box (in addition to the Enable box) if the object is included in a LonWorks network variable that is a structure of multiple data elements that should be parsed into more than one BACnet object.
Lock: Check this box if the object is the lock member of a group. This flag is only used in conjunction with the Group flag. When multiple BACnet objects are mapped to a single network variable that will be written to the LonWorks device, you have the option of that variable being updated when any member of the structure is written from BACnet (default). You also have the option of causing the entire structure to be updated ONLY when a certain member of the structure is updated. Check the Lock flag to indicate which member of a group is the Lock field. The structure will only be written when this single Lock field is updated (by a BACnet write). This allows all BACnet objects to be updated before the Lock object to result in a completely synchronous update. Do not set more than one Lock field per group as this will defeat the purpose.
NVO/NVI: Indicates the direction of data flow. NVI (at remote) means you can write data to this LonWorks variable. NVO (at remote) means you can read data from this LonWorks variable. Checking one will uncheck the other. You cannot change the direction of a network variable, therefore you must be certain this check box matches the definition of the device. Any mismatch will result in communication failure with the LonWorks device.
Default to Out of Service: Check this box if you want to (a) use an AI/BI as a writeable output object; (b) use an AV/BV as a direct write object bypassing the priority array. In both cases, the object becomes "write-only" in the sense that it will only write to LonWorks. You can still read the BACnet object from the BACnet network.
Write Lon NV on Power Up: Check this box if you want to immediately write a default value to the LonWorks NVI upon power-up. Otherwise, nothing will be written to LonWorks the corresponding BACnet object is written (applies only to writeable objects).
Default on Lon Comm Fail: Sets the BACnet object's Present Value to the default value noted above if LonWorks communications with the referenced device fails.
Default Value: This value is applied (written to BACnet object if writeable) on power-up if the "Write on Power Up" flag is set. This value is also applied as the Present Value upon LonWorks communications failure if the Default on Lon Comm Fail flag is set. Note that this is NOT the relinquish default value. This is a special case default value independent of the relinquish default found in the AV/BV objects.
Reference String: This string is simply a label that will be stored in the device for documentation purposes.
Read Button: Click this button to read the displayed object number from the Babel Buster 485XL. Upon completion, all of the windows in the section of the dialog box will be updated with values found in the device, assuming communication was successful.
Write Button: Click this button to write the displayed object number and all values displayed in the Object Mapping section of the dialog box to the Babel Buster 485XL.
The following parameters are only available when NV Type is set to Raw Data:
Raw NV Type: When parsing a structured variable into multiple BACnet objects, this field specifies the raw data type found in the respective field of the structure. These are the enumerated NVT_CAT types (found in the enumeration section of the pdf document mentioned above).
Byte Offset: Structured variables are multiple bytes in length. This column provides the byte offset from the first byte of the structure where this field or object is found.
Bit Offset: Some structured variables treat individual bits as data elements, and often there is a set of multiple bits in such a structure. The Offset column is used to access the correct byte. The Bit offset is used to specify which bit this object refers to. Bit offsets are 0..7 bit positions from the left (MSB of byte). To reiterate, a bit offset of 0 will result in a byte mask of 0x80. Keep in mind that LonWorks SNVT bit structure definitions identify "bit 1" as the left most bit.
Scale A,B,C: These are the scale factors A, B, and C whose usage is as defined for standard network variable types (see note about pdf file available above).