HV ANSI Series Technical Reference Manual, MAN0340, Rev. A
vii
Power Requirements
Power Supply Options
Depending on the current draw requirements, the terminal may require the use of different power
supplies. Use the configuration number listed below (see previous page) to determine the correct power
supply:
•
"
-1
"
—
requires connection to a 5-volt ± 5% regulated power source.
•
"
-2
"
—
requires connection to a power source between 7.5 and 12 VDC that can source adequate
current. However, depending on a unit's total current draw, an input of up to 28 VDC may be
applied. See chart on next page.
•
"
-H
"
—
requires connection to a power source between 9.5 and 28 VDC that can source
adequate current. However, input voltage is not dependent on a terminal’s current draw and
may be used with all terminal options.
Calculating Total Current Draw
The table below summarizes the current draw requirements for HV ANSI Series terminals in various
configurations (measured at its interface connector). Values listed are approximate due to variations in
individual components—actual values may vary.
Current Draw for Basic Configuration
Configuration
Description
Draw
HVR2
Base Unit with RS-232
35 mA
HVR4
Base Unit with RS-422
33 mA*
Current Draw for Options
NL
LED Supertwist Backlit
Add 185 mA
NEL/TEL
Supertwist Backlit/Extended Temperature Backlit
Add 45 mA
VFD/TVFD
Vacuum Fluorescent Display/Extended Temperature VFD Add 300 mA
KL
Backlit Keypad
Add 80 mA
LED
LED Indicators
Add 4 mA per LED
Operational Current Requirements
Handshake Low
Add 3 mA
Handshake Floating (not connected)
Add 1 mA
*Worse case measurement, based on 4000 feet of cable, terminated with a 120-Ohm resistor.
To calculate the total current draw for your terminal configuration:
1.
Read the model number on the back of your terminal.
2.
Using the model number and the table above, add the current draw for each option to that of
the base unit.
Example 1—HVNEL30R2-ANSI:
RS-232 Option
35 mA
Supertwist Backlit Display
45 mA
Calculated Total Current
80 mA
Example 2—HVNL30KLR2-ANSI:
RS-232 Option
35 mA
LED Supertwist Backlit
185 mA
Backlit Keypad
80 mA
Calculated Total Current
300 mA