DESIGNER’S HANDBOOK 4189350049C EN
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This means that if you insert high and low input error values in this case has to be calculated as the relative value
and inserted as such. The values you insert shall have a small margin to the min and max values, so in this
example you can use 400 for the low error value and use 9300 for the high. Be sure that if you lose 0V connection
to the potentiometer then the input voltage will raise to above max error value.
Worst case calculation if 0V connection is lost:
Rel. error max,
o =10000(Vref. relative value)*112kΩ/(112kΩ+5kΩ+500Ω)= 9532 so the max. error value shall be
between this value and 9167 that is the max. valid value. Therefore 9300 seems to be a good choice.
It will be the same also if you connect an external voltage source to the Vref terminal to use a higher supply voltage
for the potentiometer.
5.6.9.13
Dimmer input
AX1: +HV3/DIM on terminal 2 with 0V reference at AGND at terminal 1.
The dimmer input is a standard high-voltage input and can be configured as previously described. When used as
dimmer input, the pre-configuration is located in the Product Profile (PP), and changes can be made via the XDi
user menu.
In all DEIF standard libraries you will find product profiles for analogue dimmer connection to the dimmer input on
AX1 located in slot 1. It is important that the AX1 module is located in the correct slot specified in the PP
documentation / help-text. By default, this input is configured for potentiometer operation using Vref to supply the
potentiometer, but the analogue dimmer input can alternatively be re-configured as a voltage input via the user
menu.
This means that the dimmer level will be controlled by the voltage at terminal 2 (+HV3/DIM).
The voltage can be generated by a central dimmer controller or by a potentiometer used as variable voltage
source, as in the example below.
Independently of the analogue dimmer input configuration, the actual dimmer level can be shared via CAN, to
control other XDi units forming part of the same dimmer group as the XDi unit with the analogue dimmer input.
The supply voltage for the potentiometer in this configuration should be relatively stable since changes in this
voltage will directly affect the dimmer level. The potentiometer value is not critical in a dimmer application.
It is recommended to use a potentiometer in the range 1 to 20 kΩ.
5.6.9.14
Dimmer input using Vref
To avoid voltage fluctuation affecting the dimmer input, it is possible to use the AX1 V
ref
output as supply for the
dimmer potentiometer. Configured like that the dimmer level will be stable and independent of the supply voltage,
