AN010f.doc
PAGE
Date: 1-28-99
by Eric Sprik
Updated 5/21/01
1
INSTALLING THE HID MAXIPROX
FOR OPTIMUM READ RANGE
The HID MaxiProx has become the reader of choice for passive long range
reader applications. In some placements, read range performance is critical
to customer satisfaction. These installation guidelines will help planners and
installers maximize read range.
HID has introduced a new version of the MaxiProx called the DFM. Please
note the differences:
•
The DFM has two terminal strips. The NT has one.
•
The DFM can operate on 12vdc or 24vdc. The NT is 24vdc only.
Warning: P2 jumper must be on pins 2-3 for 24vdc!
•
The DFM tunes itself automatically, so ignore the tuning comments.
They apply only to the NT.
•
The DFM can be configured for serial output.
•
The DFM DIP switches are not the same as NT.
The MaxiProx reader requires a
linear
power supply with a
rating of 24 - 28.5 Volts DC at a minimum of 1.5 Amps per
reader. A linear power supply aids maximum reader
performance. HID recommends against using switched
supplies, as switching type supplies often interfere with effective reader
operation.
HID does not specify a single brand or model linear supply. It is
recommended that you contact a power supply manufacturer of your choice.
Ask them to specify a linear power supply that will meet the current and
voltage requirements above.
REASONS FOR USING A LINEAR POWER SUPPLY
MaxiProx readers cycle through low, medium, and high power modes.
Whenever the MaxiProx switches into high power mode it demands up to one
Amp of instantaneous current. Switching supplies monitor the output voltage
and adjust by rapidly switching current “on” and “off”. As a result, current
supply can lag behind the demand of the load. This also causes fluctuations
in the voltage of the power supply, compounding the problem. The result is a
reduced read range.
In contrast, linear power supplies are always on, ready to supply constant
voltage and current.
Application Note 010
POWER SUPPLY
