Telos Zephyr Xstream - Manual (Page 64)

USER’S MANUAL
Section 3: GUIDED TOUR of the HARDWARE 52
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 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, please contact Telos customer support.
These will 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 and external pull up resistor, unless it is built‐in to that equipment's inputs. An
appropriate value is in the range if 2.2K
Ω to 10K Ω . 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.