Understanding bindings
The address table consists of the following elements (refer to column headings in Table 38):
•Use Domain at Index: This number represents a pointer or reference to a table entry in the Domain table. For Trane devices, the value at index (or row) 0 will be a decimal 17.
•Group Number or Subnet Address field: The function varies depending on the binding type. For group bindings, the group number is stored here. For subnet/node bindings, the subnet address is stored here.
•Group Member at Node Address field: This varies depending on the binding type. The group member specifies a unique number for each member of a group binding.
•Group Size field: This specifies the total number of members in the group binding.
The address table in Table 38 shows a subnet/node binding at index 0, which lists a device at DSN
Table 38. Address table
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| Group | Group |
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| Use | Number or | Member of |
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Addr | Binding | Domain at | Subnet | Node |
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index | type | Index | Address | Address | Group Size |
0 | subnet/node | 0 | 1 | 8 | n/a |
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1 | group | 0 | 1 | 2 | 3 |
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2 | unbound |
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3 | unbound |
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14 | unbound |
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Designing bindings
On a LonWorks job, binding connections should be designed and documented just like wiring connections are designed and documented on shop drawings. Follow these rules, limits, and the methodology provided when designing bindings:
Binding rules and limits
1.Bindings can be made only between NVs that have the same network variable type (SNVT or UNVT).
For example, nvoSpaceTemp is of type SNVT_temp_p and nviSpaceT- emp is also of type SNVT_temp_p, so these two variables can be bound. Rover takes care of matching network variable types for you, but during design, this fundamental rule should be kept in mind.
2.Unique subnet/node binding types consume an address table entry on the sending device only.
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