Occupancy Arbitrator

The input pins are scheduledCurrentState, WMOverride, NetworkManOcc and OccSensorState.The output pins are EFF_OCC_CURRENT_STATE and MANUAL_OVERRIDE_STATE. This function computes the current Effective Occupancy Current State and the Manual Override State.

Inputs

Range
Input Name Low High Input Value Description
scheduleCurrentState 0 1,3,255 unconnected Schedule Current State = 255 (OCCNUL)
invalid Schedule Current State = 255 (OCCNUL)
VAL < low Schedule Current State =0 (OCC)
VAL > high Schedule Current State = 255 (OCCNUL)
WMOverride 0 1-3,255 unconnected WM Override = 255 (OCCNUL)
invalid WM Override = 255 (OCCNUL)
VAL < low WM Override = 0 (OCC)
VAL > high WM Override = 255 (OCCNUL)
NetworkManOcc 0 1-3,255 unconnected Network Man Occ = 255 (OCCNUL)
invalid Network Man Occ = 255 (OCCNUL)
VAL < low Network Man Occ = 0 (OCC)
VAL > high Network Man Occ = 255 (OCCNUL)
OccSensorState 0 1, 255 unconnected Occ Sensor State = 255 (OCCNUL)
invalid Occ Sensor State = 255 (OCCNUL)
VAL < low Occ Sensor State = 0 (OCC)
VAL > high Occ Sensor State = 255 (OCCNUL)

Occ = 0, Unocc=1, Bypass =2, Standby = 3, Null = 255

Outputs

Output Name Range Description
EFF_OCC_CURRENT_STATE 0 to 3 (Occupied, Unoccupied, Bypass, Standby) Effective Occupancy Current state
MANUAL_OVERRIDE_STATE 0 to 3, 255 (Occupied, Unoccupied, Bypass, Standby, Null) Manual Override State

Configuration:

  1. Specify Net wins (0) or Last in wins (1).
  2. Specify the occupancy sensor operation. There are 3 choices: Conference room (0), Unoccupied Cleaning Crew (1), and Unoccupied Tenant (2).

Operation

The Occ Arb Function Block has two levels of functioning. At the first level, inputs are provided to Manual Override Arbitrator. The Network Man Occ, WMOverride, and NetWins / Last-inWins is provided as inputs to Manual Override Arbitrator. The output obtained at this stage is the Manual Override state Saken which is taken as input for the next level. At the second level, Occupancy Arbitrator takes inputs from Manual Override State, Occ Sensor State, Schedule Current State, and Occupancy Sensor Operation. The final output is Effective Occ Current State.

The valid values for each of these parameters are given below:

Parameter Valid values
Network Man Occ Occ, Stdby, Byp, Unocc, Null
WMOverride Occ, Stdby, Byp, Unocc, Null
Manual Override State Occ, Stdby, Byp, Unocc, Null
Occ Sensor State Occ, Unocc, Null
Schedule Current State Occ, Stdby, Unocc, Null
Effective Occ Current State Occ, Stdby, Byp, Unocc, Null

Manual Override Arbitration Mechanism

Manual Override Arbitration mechanism determines the value of Manual Override State. This value is used as an input to the Occupancy Arbitrator.

The Manual Override Arbitrator uses either a Net Wins or a Last in Wins scheme to evaluate the inputs. Net Wins means the network command always takes precedence over the wall module command. The following truth table is followed.

Net Wins/
Last in Wins
Network
Man Occ
WM Override RESULT:
Manual Override State
Comment
Net Wins OCC Do not Care OCC Result set to Network Man Occ.
Net Wins UNOCC Do not Care UNOCC Result set to Network Man Occ.
Net Wins BYPASS Do not Care BYPASS Result set to Network Man Occ.
Net Wins STANDBY Do not Care STANDBY Result set to Network Man Occ.
Net Wins OCCNUL OCC OCC Result set to the wall module override.
Net Wins OCCNUL STANDBY STANDBY Result set to the wall module override.
Net Wins OCCNUL BYPASS BYPASS Result set to the wall module override.
Net Wins OCCNUL UNOCC UNOCC Result set to the wall module override.
Net Wins OCCNUL OCCNUL OCCNUL Override canceled.

With Last in Wins, the last override source is used to determine the final state. If multiple sources change state in the same second, they are evaluated in order: Network Man Occ, WM Override. Each second the function block is called, the algorithm looks for a change of state to Network Man Occ or WM Override. If either of these changed state, then appropriate action is taken. Generally, a new command on any input cancels prior action by another source.

Net Wins/
Last in Wins
Network
Man Occ
(note2)
WM Override
(note 2)
RESULT:
Manual Override State
Comment
Last in Wins OCC Do not Care OCC Result set to Network Man Occ.
Last in Wins UNOCC Do not Care UNOCC Result set to Network Man Occ.
Last in Wins BYPASS Do not Care BYPASS Result set to Network Man Occ.
Last in Wins STANDBY Do not Care STANDBY Result set to Network Man Occ.
Last in Wins OCCNUL Do not Care OCCNUL Override canceled.
Last in Wins Do not Care OCC OCC Result set to the wall module override.
Last in Wins Do not Care STANDBY STANDBY Result set to the wall module override.
Last in Wins Do not Care BYPASS BYPASS Result set to the wall module override.
Last in Wins Do not Care UNOCC UNOCC Result set to the wall module override.
Last in Wins Do not Care OCCNUL OCCNUL Override canceled.

Note:

This function block does not have the ability to trigger on a network variable update. This differs from E-Bus Mechanisms which state the node should do the bypass timing for the network Manual Occupancy Command and reload the timer when a BYPASS update occurs.

From iteration to iteration of the Function Block, the Occupancy Arbitrator keeps track of the last state of the Network Man Occ and WM Override inputs so that it knows when a transition occurs. On power up/reset the last latch value is set to FALSE, regardless of the negation configuration. Override is canceled after a power outage. The Network Man Occ and WM Override inputs must reassert themselves after a power outage.

Network Manual Occupancy Input

Network Man Occ is a method to command the occupancy state from a network workstation or a node. The user may write logic to combine these if both are required for the application. Network Man Occ can command the state to be occupied, unoccupied, standby, bypass or null. It is required that the workstation (nviManOccCmd) or network node (nviBypass) perform any timing needed (i.e. bypass).

WM Override Input

WM Override is a method to command the occupancy state from a locally wired wall module. WM Override can command the state to be occupied, unoccupied, standby, bypass or null. It is required the function block wired to this input perform any timing needed (i.e. bypass). Note: the current T7770 wall module function does not support occupied or standby override, but future wall modules might.

Occupancy Arbitration Mechanism

The Occupancy Arbitrator computes the effective occupancy status. The inputs of the Effective Occupancy Arbitrator include the Schedule Current State, Occ Sensor State, and Manual Override State. The Manual Override State comes from above.

The Effective Occupancy Arbitrator sets the Effective Occ Current State. Valid states of current state are:

OCCNUL is not a valid output. If all inputs are OCCNUL, the output is set to occupied.

 

Manual Override
State
Schedule
Current
State
Occ
Sensor
State
Occ Sensor Operation RESULT:
effOcc
CurrentState
Comments Follows LonMark SCC
OCC Do not Care Do not Care Do not Care OCC Result = Manual Override State Yes
STANDBY Do not Care Do not Care Do not Care STANDBY Result = Manual Override State Yes
UNOCC Do not Care Do not Care Do not Care UNOCC Result = Manual Override State Yes
BYPASS OCC Do not Care Do not Care OCC Result stays at occupied because bypass is not effective when scheduled for occupied. Yes
BYPASS STANDBY Do not Care Do not Care BYPASS Result stays at bypass. Yes
BYPASS UNOCC Do not Care Do not Care BYPASS Result = bypass Yes
BYPASS OCCNUL OCC Do not Care OCC Result follows occupancy sensor Yes
BYPASS OCCNUL UNOCC Do not Care BYPASS Result follows manual override Yes
BYPASS OCCNUL OCCNUL Do not Care OCC When occupancy sensor is null, default to occupied. Yes
OCCNUL STANDBY Do not Care Do not Care STANDBY Result = scheduled state. Yes
OCCNUL OCC OCC Do not Care OCC All say we are Occupied. Yes
OCCNUL OCC UNOCC Do not Care STANDBY We are schedule to be occupied but room is actually unoccupied, so go to standby to save energy. Yes
OCCNUL OCC OCCNUL Do not Care OCC Sensor not present so use schedule. Yes
OCCNUL UNOCC UNOCC Do not Care UNOCC All say we are unoccupied. Yes
OCCNUL UNOCC OCCNUL Do not Care UNOCC Sensor not present so use schedule Yes
OCCNUL OCCNUL OCC Do not Care OCC Result -= occupancy sensor state. Yes
OCCNUL OCCNUL UNOCC Do not Care UNOCC Result -= occupancy sensor state. Yes
OCCNUL OCCNUL OCCNUL Do not Care OCC Result = occupied because the LonMark SCC sets a null occupancy sensor to Occupied. Yes
OCCNUL UNOCC OCC Conference Room UNOCC Stay unoccupied regardless of what the sensor says (i.e. save energy). Yes
OCCNUL UNOCC OCC Cleaning Crew STANDBY We are schedule to be unoccupied but the room is actually occupied, so go to standby for the comfort of the cleaning crew. No
OCCNUL UNOCC OCC Tenant OCC We are schedule to be unoccupied but the room is actually occupied, so go to occupied for the comfort of the tenant. No