DNT-T103 & DNT-T221 Application Guide
Page 30 of 41 Document Edition 4.1
output is a combination of its function and type (as obtained from the tables on the previous page)
according to the following formula:
Output Configuration Code = Output Function Code + Output Type Code
For example: To configure Output 1 on a DNT-T221 as a direct acting analog output for first stage
heating, enter the number 10.4 into AV21 (where 10 is the function and 0.4 is the type, so 10 + 0.4
=10.4).
1. B
INARY OUTPUTS
If the binary output is selected as M
UX it simply transfers the value written to the corresponding variable
(AV1, AV2 or AV3) to the physical output. There is no delay.
If the binary output is controlled internally by the BACstat II, then it will have a delay-on that is
specified by its corresponding setup variable. This value is in seconds.
Physical Output Associated AV Delay Setup Variable
OP1 AV1 AV24
OP2 AV2 AV26
OP3 AV3 AV28
2. PULSE WIDTH MODULATION OUTPUTS (PWM)
The Pulse Width Modulation scheme used on the BACstat II is applicable to the Belimo NM24
actuator.
An analog value is converted to a variable duty cycle pulse that has minimum and maximum pulse
times as determined by setup variables. For example, a Belimo PWM actuator uses a minimum value of
0.59 sec., and a maximum value of 2.93 sec. The O
N portion of the pulse then stretches from 0% @
0.59 to 100% @ 2.93.
If the output using PWM is also configured as reverse acting then the output device will be considered
to be reverse acting (i.e., Normally Open) and the input value will be inverted internally before being
applied to the physical output. The actual action of the physical output will be direct.
If the PWM output is not being used for a Belimo device then the minimum and maximum values can
be changed to what ever is required. Also, Belimo actuators may be configured to use a 0.5 to 25.5
signal instead, which may be more suitable in many cases (i.e., variable values of 50 and 2550).
Physical Output Associated Output AV Min. Setup Variable Max. Setup Variable
OP1 AV1 AV24 AV25
OP2 AV2 AV26 AV27
OP3 AV3 AV28 AV29
The value (in seconds) is shifted by two decimal places when entered in the variable. Default values are,
Minimum PWM Value = 59 Maximum PWM Value = 293
3. T
IME PROPORTIONED (TP)
The DNT-T103 can have up to two stages of Time Proportioned heat (Outputs 2 and 3), while the
DNT-T221 can have one stage (Output 3). These are similar to the PWM outputs except:
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