[4-wire System] Is the unoptimized Indoor Phone compatible with the optimized Outdoor Camera?
Yes. But in that combination, the doorplate backlight of Outdoor Camera will not illuminate and it performs poorer audio&video effect compared to the kit of both optimized devices.
[4-wire System] Can UTP5 or UTP5E cable be applied to connect Indoor Phone to Outdoor Camera?
To ensure the stable performance, make sure that the standard cable configuration is applied as below:
when length between Outdoor Camera and Indoor Phone is within 50m, adopt cable AWG20;
when length between Outdoor Camera and Indoor Phone is within 100m, adopt cable AWG18.
[4-wire System] Cannot make a call on Outdoor Camera to Indoor Phone.
Check the wiring of port audio and shared ground.(White: audio; Black: shared ground)
[4-wire System] Which call will be received by when two calls are placed on two Outdoor Cameras?
The one placed later will be received by the Indoor Phone.
[4-wire System] How many Outdoor Cameras can an Indoor Phone support?
2 Outdoor Cameras.
[4-wire System] What should we notice when selecting e-lock connected to Outdoor Camera?
The e-lock should be with unlock current within 0.8A~1A.
[4-wire System] Too short unlock time.
The Outdoor Camera provides transient on-off signal, pls select the e-lock with unlock time function.
[4-wire System] Cannot unlock the lock connected to Outdoor Camera.
The for Singnal Unlock way, e-lock requires power supply. Check the wiring. For details, refer to the user manual.
[4-wire System] How to unlock the door?
It is only available during talk.
[4-wire System] Voice sounds on Indoor Phone but no image (or blue screen).
Make sure that Pin 4 (video input) on Outdoor Camera and of Port OUTDOOR on Indoor Phone are connected.
[4-wire System] Display of Indoor Phone turns to be b/w in nighttime?
Due to the IR light compensation adopted in Outdoor Camera, the display will transfer to be b/w automatically in low illumination to ensure the image clarity.
[4-wire System] Indoor Phone displays in B/W.
1. Check the device model. If model numbers of both the Indoor Phone and Outdoor Camera contain C,the display of Indoor Phone is color. If one model number of the two devices dosenot contain C, the display will be b/w.

2. Adjust the video chroma on color Indoor Phone. For detailed operation, refer to the user manual.
[4-wire System] No ringing when the Indoor Phone is called.
Adjust the ringing volume of the Indoor Phone. For detailed operation, refer to the user manual.
[4-wire System] Device not work after being electrified.
Check the polarity of the power cable connection. Make sure the power is on.
[4-wire System] Whistle problem
1. The volume gain of Outdoor Camera or Indoor Phone is too strong.Turn the gain adjustment knob of Outdoor Camera or adjust the talk volume of Indoor Phone. For detailed operation, refer to the corresponding user manual.

2. Improper installing location would cause the whistle problem. Avoid to install the devices in the narrow space or at the corner.
[4-wire System] Low talk volume
Adjust the talk volume of the Indoor Phone or Outdoor Camera. For details, refer to the user manual.