Siemens BACnet ATEC 125-5050 - Manual (Page 28)

Chapter 3 – Point Database
28
Siemens Industry, Inc.
BACnet ATEC Owner's Manaul
125-5050, Rev. AA 4/20/2010
Descriptor Address 1 Application Description
FLOW {75} 2 All except 2597 Indicates the amount of air currently passing the air velocity
sensor. The value is calculated as a percentage based on
where the value of AIR VOLUME is in the range between 0
and CTL FLOW MAX.
CTL FLOW MIN {76} 2 All except 2597 The active minimum flow used as a limit for the flow control
loop. This value is the same as CLG FLOW MIN if the
controller is in cooling mode, or is the same as HTG FLOW
MIN if the controller is in heating mode, unless it is overridden.
CTL FLOW MAX {77} All except 2597 The active maximum flow used as a limit for the flow control
loop. This value is the same as CLG FLOW MAX if the
controller is in cooling mode, or is the same as HTG FLOW
MAX if the controller is in heating mode unless, it is
overridden.
CTL TEMP {78} All except 2597 The temperature used as input for the temperature control
loops. This value is the same as the value in ROOM TEMP
and RM TEMP OFFSET unless it is overridden.
CLG LOOPOUT {79} All except 2597 The cooling temperature control loop output value in percent.
HTG LOOPOUT {80} All except 2560, 2597 The heating temperature control loop output value in percent.
AVG HEAT OUT {81} 2 2562, 2564, 2566 This point is used to determine what stages of electric heat
are used for a given loop output value. The ranges for the
value are determined by the number of stages used: 0 to 100
for 1 stage of electric heat, 0 to 200 for 2 stages of electric
heat, and 0 to 300 for 3 stages of electric heat.
With electric heat, this value is equal to: HTG LOOPOUT ×
STAGE COUNT.
STAGE MAX 82 2562, 2564, 2566 The value, in percent, which the heating loop must exceed for
the electric heat to be ON for the full duty cycle (STAGE
TIME).
STAGE FAN 83 2565, 2567 The valve must be opened greater than this value before the
fan will turn ON.
STAGE MIN 83 2562, 2564, 2566 The value, in percent, which the heating loop must go below
for the electric heat to be OFF for the full duty cycle (STAGE
TIME).
DMPR STATUS {84} 2 2560, 2561, 2562,
2563
This point is used only when CAL MODULE set to YES. It
readjusts the damper position if the command value is not
equal to the actual position of the damper. CAL indicates that
the damper is operating normally. RECAL indicates that the
damper position was adjusted (recalibrated) by 25% because
the desired airflow was not obtainable under its current status.
SWITCH LIMIT 85 All except
2560, 2561, 2597
The active temperature control loop output must be less than
this value to switch between cooling mode and heating mode.
Actual switchover depends on SWITCH DBAND being
exceeded and is subject to SWITCH TIME being expired.
SWITCH TIME 86 All except
2560, 2561, 2597
The time, in minutes, before the heat/cool mode can change
over when the other parameters are appropriate.
STAGE COUNT 88 2562, 2564, 2566 The number of electric heating stages used by the application.
DOs associated with unused stages may be used as spare
DOs.
VALVE COUNT 88 2563 The number of heating valves available.
STAGE TIME 89 2562, 2564, 2566 The cycle time in minutes for the electric reheat stages. For
example, if there are three stages of electric heat and STAGE
TIME = 10 minutes, STAGE COUNT = 3, and AVG HEAT
OUT = 150% then, Stage 1 is ON for 10 minutes (100% of the
time), Stage 2 is ON for 5 minutes (50% of 10 minutes) and