DNS-24, DNT-T103 & DNT-T221 Application Guide
Page 14 of 43 Document Edition 4.2
Refer to the Application section of this guide for further detail on each of these control strategies, on
page 21.
*Although possible, this is not recommended because it can cause excessive network traffic.
2. ALGORITHM MODE
The application control strategy operates in one of the following basic modes, as determined by the
Algorithm Mode variable (AV13).
VAV Only: Forces the box to its minimum position
VAV Only: Forces the box to its maximum position
VAV Only: Forces the box to its fully closed position
VAV Only: Forces the box to its fully open position
VAV Only: Forces calibration of the bias so the airflow reads
zero at current conditions. This assumes that the Air Handler has
been shut down and that there is no air flow at the box.
All heating control and associated icons are completely disabled
(as though no heating stages even exist)
All cooling control and associated icons are completely disabled
(as though no cooling stages even exist)
Both heating and cooling control and their icons are disabled
Unless the fourth digit of the Display Code (AV15) is set to 1 or 5, or Fan Control is configured as
Manual, the top two buttons on the BACstat – OFF (O) and ON (I) – will switch between Night and Day
modes. Changing to the other modes for VAV is keypad accessible in Air Balancer mode within the
Service Tool menus. The Alg. Mode (AV13) is also fully accessible from another device over the
network (via GCL+ or ORCAview OWS or 3
rd
Party devices), to command it to any mode as required
(including the lockouts).
Lockout Modes
Heating and cooling lockout modes are operational for all Control Applications.
Basically, once a BACstat has been configured for various stages of heating and cooling, either the
heating and/or cooling may be disabled on the fly as necessary for various control strategies simply by
commanding the Alg. Mode (AV13). In all other regards, control continues to function the same as it
would when in Occupied mode.