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VPX vs G3X Problem: G3X Discrete input from VPX

8MikeXray

Well Known Member
I have a VPX that is showing 2.9 volts on pin J1-2 that is set up to provide a high discrete signal (Boost Pump on) to my G3X. This voltage is present even though all of the current faults are selected off. The GSU73 sees this voltage and thus the G3X considers the high discrete active. I have checked other VPX outputs and they to also show the 2.9 volts. I understand that the 2.9 volts is present to allow the option of seeing a current fault, if selected, on a device.

How do I get an active high to work in this situation with the G3X?

Thanks
 
Discrete Input Parameters

I have a VPX that is showing 2.9 volts on pin J1-2 that is set up to provide a high discrete signal (Boost Pump on) to my G3X. This voltage is present even though all of the current faults are selected off. The GSU73 sees this voltage and thus the G3X considers the high discrete active. I have checked other VPX outputs and they to also show the 2.9 volts. I understand that the 2.9 volts is present to allow the option of seeing a current fault, if selected, on a device.

How do I get an active high to work in this situation with the G3X?

Thanks

Hi Mike,

Do you possibly have your discrete input on the G3X set to Active Low? 2.9v would be set as active, if the G3X input were set to Active Low. If set to Active High, 2.9v would be determined to be inactive.

From the G3X Touch Installation Manual:

When configured as Active Low, the inputs conform to the following specification:

ACTIVE: Vin < 3.5 VDC, or Rin < 375 Ω
INACTIVE: Vin > 8 VDC, or Rin > 100k Ω

When configured as Active High, the inputs conform to the following specification:

ACTIVE: Vin > 8 VDC, or Rin > 100k Ω
INACTIVE: Vin < 3.5 VDC, or Rin < 375 Ω


Thanks,

Justin
 
The GSU73 pinout diagram has an asterisk next to all 4 of the discrete inputs, mentioning that they're active low. Are these pins able to be configured for active high? Since they're default active low and the voltage is less than 3.5, it makes sense that they would be active in this setup. Possibly swap to an analog hi input pin, ground the associated low pin, and set your alert in the configuration menu to be active high > 8 volts.
 
Discrete

I ended up changing it to an active low and got it working correctly by adding a diode to the boost pump switch input on the VPX. For some reason the VPX was triggering the active low constantly regardless of the switch position. The diode did the trick. Now I get the boost pump annunciation on the G3X when either the stick switch or the panel switch is selected on.
 
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