Universal Douglas Wlc-4150 Dialog Lighting Control Unit User Manual

universal douglas WLC-4150 Dialog Lighting Control Unit User Manual

General Information

The WLC-4150 implements a list of BACnet objects that monitor and control associated Dialog objects. 

• Follows BACnet Standard Revision 17
• Uses BACnet Application Specific Controller profile.
• Supports COV Subscriptions
• Supports Read-Property-Multiple
• Support remote device reinitialization
• Supports command prioritization

Out-of-service flag

All WLC-4150 BACnet objects contain a writable out-of-service flag. This flag is used by operator workstations to disconnect a BACnet object from its physical output. The out-of-service flag is not an indication from the 4150 that the associated Dialog object is unresponsive. All out-of-service flags have a default value of false on powerup.

Setting an input object’s out-of-service flag to true causes it to hold its most recent present-value. It no longer updates as the associated Dialog object changes. In this state the present-value can be written but this has no effect on the associated Dialog object. The present-value of input objects can not be written while the out-of-service flag is false. It works this way to comply with the BACnet standard.

Setting a value object’s out-of-service flag to true causes the same behaviour as input objects: The present-value remains writable but no longer has an effect on the associated Dialog object.
In BACnet systems with multiple workstations it is possible for one to prevent all others from properly controlling a piece of equipment by setting an object’s out-of-service flag to true.

Network-Port Object

The WLC-4150’s IP Address, Default Gateway, Subnet Mask and BACnet UDP port can be changed through the network-port object (PORT1). Writing to other properties such as the MAC Address will result in an access denied error message. Writing to these properties does not have an immediate effect. The 4150 will not change its network settings until it is power cycled. The changes_pending flag indicates that a restart is required to complete the update. A restart can be initiated over BACnet with the device reinitialization command.

BACnet and network settings can also be changed through the 4150s touch screen. The IP, Subnet, and Gateway menu is under Settings-> System Settings->Network Settings. The BACnet port is under Settings->BACnet Settings.

Device Reinitialization Command

The WLC-4150 responds to device control reinitialization commands with a hard reset in all cases. The primary purpose is to reinitialize networking based on new parameters specified by the network-port object. The reset is effectively the same as power cycling the 4150.

Reinitialization is not password protected. If your workstation asks for a password it can be left blank. Options like Cold-start, Warm-start, etc all result in a complete system restart.

Device Object

The WLC-4150’s device object allows workstations to view the main system parameters. Device time, object list, location etc. The location, device name, device ID, and description can all be written and will maintain their new values through power cycles. The factory default device name is “4150 BACnet Native”. The default Device ID is 4150. On sites with multiple WLC-4150’s these parameters need to be changed to unique values. Changes to these parameters occur immediately. A device reinitialisation is not required.

The 4150 can potentially contain so many BACnet objects that the device object list is longer than the maximum packet size. In this situation a segmentation-not-supported error is sent. A list of the device object can still be obtained by reading each index of the object list individually. Most BACnet workstations do this automatically.

Command prioritization

MultiState values and Analog values support standard BACnet write-property command prioritization. They maintain an array of present-values and the priority these were assigned during the write. If a write is made with a lower priority than one in the array the present-value maintains the higher priority value. A write with an empty (null) priority will change the present-value regardless of the priority array.

Elements can be cleared from the priority array with writes of null present-value and a specified priority. If the cleared value is the one presently being used the present-value will change to the next highest priority element in its array. The relinquish default parameter is also supported. This is the present-value an object will go to if all elements in its priority array are cleared.

On powerup all priority arrays and relinquish default parameters are cleared. It is up to workstations to query the 4150’s priority arrays and default parameters then write to them again.

COV subscriptions

The WLC-4150 supports COV subscriptions. COV is an alternative to repeatedly polling an object for changes to its present-value. Updates are automatically sent to the subscriber when a value has changed. Analog inputs and Analog values support the COV increment parameter. This controls how much of a change is required to trigger the notification. Writing to an Analog value’s present-value can trigger it to send a notification. Writes to an object’s out-of-service flag also trigger a COV notification.

COV subscriptions can be infinite or of a finite lifetime. They can also be terminated with a cancel COV subscription command. All COV subscription information is lost when the 4150 power cycles. It is up to BACnet workstations to query the 4150’s ActiveCOV-Subscription list and issue new subscription commands when this happens.

BACnet Object Names & Numbering

The WLC-4150 automatically generates names for its BACnet objects based on the Dialog object they read/write. For example the MultiState value controlling individual relay 56-3 will be assigned the BACnet name of “Individual Relay Control 56-3”. The 4150 touchscreen allows Dialog objects to be manually assigned names such as “Atrium Entrance”. User assigned names are added to the BACnet name in brackets. Ie: “Individual Relay Control 56-3 (Atrium Entrance)”.

When the 4150 is queried for its list of objects it only responds with Dialog Objects that exist. A Dialog object exists if it was discovered on the Dialog bus or manually added through the 4150 touchscreen. Without this feature there would be thousands of useless BACnet objects present. This process does not effect the numbering (Object-IDs) of BACnet objects. Ie: BACnet Analog Input 4 will always correspond to Dialog Individual Dimming Status 2-1. The Appendix contains a complete list of how every possible BACnet Object maps to Dialog.

When a new device is added to the Dialog bus a corresponding BACnet object is generated within two minutes. Workstations typically don’t expect object lists to grow. An operator may need to have the workstation re-read the 4150’s device object list. If a device is removed from the Dialog bus its corresponding BACnet object is not automatically removed. It will remain present until deleted using the 4150’s touch screen.

MultiState Variables

MultiState inputs and MultiState values have three possible present-values (1=OFF, 2=ON, 3=NA). The state names are transferred to workstations through the BACnet state text property.
NA represents a Dialog object which is no longer present in the system because it has been disconnected or deleted. Attempting to write Off/On to these objects will not have any effect as there is no Dialog object to control. The present-value will return to NA.
Workstations may set a working MultiState present-value to NA. However this will have no effect on the Dialog system. The BACnet present-value will become NA but the Dialog object it controls will remain at its last Off/On state.

MultiState Inputs

MultiState inputs are used by workstations to read the values of the following Dialog objects: 

• Group Status [ 0 – 127]
• Preset Local Status [ 128 – 639]
• Preset Global Status [ 640 – 1151]
• Individual Relay Status [1152 – 1407]
• Occupancy Individual Status [1408 – 1663]
• Occupancy Group Status [1664 – 1791]
• Occupancy Preset Local Status [1792 – 2303]
• Occupancy Preset Global Status [2304 – 2815]

MultiState inputs are intended to be read only. The present-value may be written if the out-of-service flag is set to true, but this does not effect the Dialog object.

BACnet Object Names & Numbering

Multistate Values

MultiState values are used to control the following Dialog objects:

• Group Control [ 0 – 127]
• Preset Local Control [ 128 – 639]
• Preset Global Control [ 640 – 1151]
• Individual Relay Control [1152 – 1407]

Analog Variables

Analog values are used to control the following Dialog Objects:

• Individual Dimming Control (0-100%) [ 0 – 255]

Dimmers are internally stored as integers between 0 and 100%. The BACnet interface allows real values such as 3.14 to be written to dimmers, however these will be read back as rounded whole numbers.

Analog Inputs

Analog inputs are used to read the present-value of the following Dialog objects: 

• Individual Dimming Status (0-100%) [ 0 – 255]
• Local Photo Sensor Status (Lux) [256 – 319]
• Global Photo Sensor Status (Lux) [320 – 383]
• Temperature Sensors (°C) (for Future) [384 – 639]

Analog inputs are intended to be read only. The present-value may be written if the out-of-service flag is set to true, but this value does not effect the Dialog object.

Relay Status

Multi-State Value = READ ONLY
Values 1=OFF, 2=ON, 3=NA

Relay Control

Multi-State Value – READ/WRITE
Values 1=OFF, 2=ON, 3=NA

Individual Dimmer Status

Anaglog Input – READ ONLY
Values 0-100

Individual Dimmer Control

Anaglog Value – READ/WRITE
Values 0-100%

Group Status

Multi-State Input – READ ONLY
Values 1=OFF, 2=ON, 3=NA

Group Control

Multi-State Value – READ/WRITE
Values 1=OFF, 2=ON, 3=NA

Preset Local Status

Multi-State Input – READ ONLY
Values 1=OFF, 2=ON, 3=NA

Preset Global Status

Multi-State Input – READ ONLY
Values 1=OFF, 2=ON, 3=NA