The CNX-P1260 (Versions 1.5 and above) includes a new feature that allows you to remotely start and stop the PSU. This feature is called “Pulse Start”. This feature would normally be used in conjunction with a wireless device such as a car alarm with auxiliary inputs/outputs or a WiFi device with Wake-On-LAN (WOL) features.
6.1 Pulse Start Connections
The Pulse Start input can either be an externally applied voltage (ie +5v or +12V) pulse, or a momentary relay contact closure. The externally applied voltage pulse is connected to Pin 1 of J1 using the Blue wire. The momentary relay contact closure is connected to Pins 1&2 of JP1 (see Section 2.2 for location). You can use either or both of these connections to start/stop the PSU.
6.2 Pulse Start Operation
6.2.1 What is a pulse?
Voltage Pulse on Pin 1 of J1
When connecting to Pin 1 of J2, the “pulse” must be a voltage that transitions from 0V to +V, and then transitions back to 0V. The SSC will wait (hang) if the voltage stays high without going back to 0V after the initial transition from 0V to +V.
The value of the +V can be any voltage from approximately +2V to +20V. Typical voltages are +5V or +12V. The value of 0V must be below +.2V or open circuit (ie you could drive this input with a relay that momentarily connects to a +12V source and then provides an open circuit).
The current required to drive this input is very low (milliamps).
Contact Closure Pulse on Pins 1&2 of JP1
When connecting to Pins 1&2 of JP1, the “pulse” must be a low resistance metallic contact closure (ie relay) that transitions from OPEN to CLOSED, and then back to OPEN. The SSC will wait (hang) if the contact closure remains CLOSED after the initial transition from OPEN to CLOSED.
The current passing through this relay is very small (milliamps) so a low power relay can be used.
The pulse width can be any value from a minimum of approximately 100mSec to several seconds. As mentioned above, if the pulse is very long the SSC will wait for the transition back to the normal state before continuing.
6.2.2 Starting the PSU with a pulse
When the PSU is in Idle State (both LEDs off) and an externally applied pulse is applied to the Pulse Start input, the PSU will power up normally, as it would if the Ignition line had gone high. During the Bootup Lockout State any input pulse is ignored.
6.2.3 Stopping the PSU with a pulse
After the normal power up sequence, and while in Runs State, the SSC monitors the Pulse Start input for a shutdown pulse. If a single shutdown pulse is sensed, the PSU goes into the Shutdown Delay State. However, if control has been passed to the Ignition line (see Ignition Override below) the Pulse Start input is ignored.
6.2.4 Prolonging the Shutdown Delay State
If, while in the Shutdown Delay State, a single pulse is detected, the Shutdown Delay is restarted at its original value in order to prolong the Shutdown Delay. This is useful for occasionally downloading large files that would take longer than the normal Shutdown Delay time.
Once the Shutdown Delay has timed out, the PSU enters the Shutdown Lockout State. At this point the SSC ignores any pulse input until the PSU enters the Idle State.
6.2.5 Shutting down the PSU with double pulses
If two pulses are detected within a 5 second window during the Shutdown Delay State the PSU will skip any remaining Shutdown Delay Time and immediately enter the Shutdown Lockout Sequence. This feature is useful for shutting down the CarPC when your file transfer process is completed.
6.2.6 Ignition Override
If, after the PSU has been started by a pulse, the Ignition is turned on, control is passed to the Ignition line. Once the Ignition line has gained control of the SSC it will be able to shutdown the PSU as if it had initially started it. This feature is useful when you wish to remotely start the CarPC with your wireless device, but then get into your car and drive.