Telos Zephyr Xstream - Manual (Page 44)

USER’S MANUAL
Section 3: GUIDED TOUR of the HARDWARE 32
Parallel Outputs 0‐7
Outputs are open collector to ground and can sink up to 125 mA of current each (actually, any
output can sink up to 400 mA, however the maximum combined current should be kept below
1000 mA).
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IMPORTANT!
Outputs on the Zephyr Xstream motherboards prior to Rev G (1401-0000--007) cannot be
used with external pull-ups higher than 5 volts.
If this ability is required contact Telos Systems Customer Support.
These include a 10k‐ohm 5 volt pull‐up resistor to allow direct interface with 5 volt logic inputs
on other equipment. If your other equipment uses a voltage greater than 5 volts, you will need
an external pull up resistor, unless it is built‐in to that equipment's inputs. An appropriate value
is in the range if 2.2KΩ to 10KΩ. Operation with logic inputs requiring a voltage less than 5 volts
is not possible.
If used with a relay or LED, then tie your external power source ground to pin 25 (or use the 5
VDC power supplied on pin 1) and run this power source through your device, with a resistor in
series to limit maximum current to less than 125 mA.
The outputs can also be used for monitoring the status of the unit. This functionality can be set
by several menu selections in SYSTEM menu. Refer to Section 11.5 (Detailed Menu Reference)
for the menu selections relating to these outputs.
+5 VDC
(400 mA max)
OUTPUT
Equivalent schematic for the Parallel Outputs.
An external pull up resistor can be used if voltages greater than 5 volts are used. Alternatively, a
voltage source (such as the 5 volts on pin 1) can be driven through an external device (such as a
relay or LED) into the input.