Danfoss VLT HVAC Drive Instruction Manual page 12

The references will now need to be defined. This is done in the P 3‐1* parameter group. P 3‐10,
P 3‐15, P 3‐16 & P 3‐17 are all parameters that will allow you set up the reference sources. If you
want to use multiple reference points, then they must also be defined here. Most applications will
only use one reference terminal rather than multiples. If using only one reference terminal, set the
single reference source in P 3‐15, and program all other resources to [0] No Function. This is good
practice because of the Sum function described earlier.
Note: If other terminals are programmed as reference resources but not actually used, any signal
that is present on those terminals will be summed into the total reference value.
After the reference sources have been defined, the next step is to scale them. The analog inputs
are programmed in P 6‐1* & P 6‐2*. For the example above, Analog Input 53 must now be scaled.
You will need to set a low and high voltage or current as well as a low and high reference value.
See below.
Be aware that if multiple reference sources are chosen, then each can be scaled individually to
contribute the desired portion of your maximum reference.
Example: Analog Input 53 = 0‐10 V = 0‐50 Hz & Analog Input 54 = 0‐10 V = 0‐10 Hz. Now Analog Input 53 will
command the first 50 Hz and Analog Input 54 will act as a trim for the last 10 Hz.
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