Some common problem solutions
1.Devices failures due to incorrect power connection.
Instructions: There are usually several power issues leading to devices failures such as incorrect power lines or power voltage, low power ( or insufficient diameter for a certain power lines and excessive voltage drop, etc.) , short and open circuits as well as transient overvoltage of transmission lines for power system, particularly for incorrect power-up and transient overvoltage issues that make devices break down occasionally.
2. Wiring Issues.
Instructions: Sometimes failures happen resulting from wiring issues, particularly from loose connection of wiring with devices, which leads to open and short circuit,defective wiring insulation,false wiring as well as damage and performance reduction for devices. Of course bad-quality connectors inside device and poor wiring processing are also some main reasons behind failures.
Under such condition, it is important to be patient and find a certain bad connection wires resulting in specific issues. For example, the solution to the issue that picture signal is normal for a three-variable lens camera but lens can not be controlled is to check lens control wire instead of video output wire. In addition, it remains a high demand towards welding process, SYV connection and installation process for device connectors, especially for BNC type connector. Any ignorance of connectors processing can cause potential work problems even though everything performs well in debugging and test run phase. Pan/Tilt camera with omnidirectional mobility draws a particular attention to us as lines easily fall off and get broken in the long run, which means devices chosen and wiring connections should conform with strict requirement for normal and long-term operation.
3. Problems emerges because of devices or components quality.
Instructions: Generally speaking, quality issue is very rare for commercialized devices or components after careful selection.Even issues happens, it usually comes after a long-term operation for devices. Apart from some reasons mentioned above, there usually seems to be incorrect adjustment for devices leading to failures. Poor focus or focus-out phenomenon under operation toward three variable lens usually happens due to wrong adjustment. Besides, other adjustments such as camera switches, adjusting knob, decoder code switches or any other adjustable parts can affect normal operation or system performance for devices.
4. Wrong connection way among devices or components.
a. Issues relies on impedance mismatch. For example when video is connected with a monitor that is with high resistance some phenomena like excessive brightness images, jittering characters, sporadic character emerge sometimes.
b. Communication interfaces or mode problem.Such kind of problems often exists between control host and some communication control devices like decoder or control keyboard. It’s true that communication modes or transmission control codes usually vary from different suppliers so it is important to choose same brand control host, decoder and control keyboard,etc.
c. Insufficient driving capability or connected devices beyond the quota. For example, there is specific quantity limitation towards total master and sub keyboards for a control host and system can’t work normally if total devices exceed the quota. Pan/Tilt work condition is easily affected when decoder PT work power is lower than actual required one.
5. Pan and tilt problem.
Instructions: Several following factors usually lead to pan/ Tilt problems apart from product quality. Firstly the Pan/Tilt that only allows camera to be installed above its turntable is fixed in a wrong way by putting cameras below its turntable, which increases Pan/Tilt run burden and damages driving mechanism or even burns electric machine of pan tilt.
Secondly total weight of camera and its shield is beyond limit of Pan/Tilt, particularly for outdoor applications where excessive shield weight prevents Pan/Tilt from operating normally(especially with vertical direction). Pan/Tilt in outdoor applications is also easily faulty due to high or low temperature as well as a lack of waterproof and freeze-proofing protection.
6.Over long distance, decoder doesn’t work to support keyboard on controlling camera(lens) and Pan/Tilt remotely.
Instructions: The reason behind this problem is because control signal received by decoder is too weak after serious attenuation in the long distance. At this point, putting a trunk box in between properly is a good idea to strengthen control signal.
7. Low image contrast and fade image issues for monitor.
Instructions: Problems of such kind is resulting from long distance transmission or excessive attenuation for video transmission lines in addition to quality of control host and monitor. Some devices for amplifying and compensating circuit should be added now to resolve issue.
8.Image is blurry and some details may be lost with color signals missing and chroma decreasing.
Instructions: Excessive loss of high frequency parts from image signals is what make such issues happen after frequency more than 3MHZ disappears. In order to fix this, you can check whether transmission distance is too far under condition without amplifying and compensating devices installed or see whether cable distribution capacity of video transmission is too large. Sometimes it is also caused by intensive distribution of equivalent capacitance between core wire of transmission line and shielded wire.
9. Tonal Distortion
Instructions: Tonal distortion appears easily under circumstance of baseband video transmission over long distance.
10.Invalid keyboard operation
Instructions: Basically it happens when operation keyboard crashes if wiring connection is correct. You can refer to instructions of keyboard about solution to crash such as by resetting it. If such issue still exists then perhaps you can replace a new keyboard.
11. Incomplete image switches from control host.
Instructions：After switch process, there are other interference pictures overlaying current picture or HSYNC interference from other pictures, which appears because matrix switch of control host is bad not satisfying images separation requirement. It may be excessive cross modulation and inter-modulation in system leading to incomplete image switch if it is RF transmission system.
A large-scale TV monitor system, combing with burglar alarm system, is a complicated and high-tech project. A careful selection of high-quality devices and standard construction according to strict regulations are the key steps to ensure normal work condition in the long run. An attitude of analyzing and considering issues calmly also plays an important role resolving problems while removing devices aimlessly and casually only worsens current situation.
Instructions: It may be communication line issue when controlled Pan/Tilt or motorized lens move unstably or nonstop. If wiring and connection are correct, you can check matched resistance(120¦) of communication terminal from RS-485 in decoder or cut off host interface and far end of matched resistance, followed by measuring RD DC resistance of port pin from single communication chip and R2 DC resistance of whole system communication interface with multimeter. Measurement results can be compared with theoretical value with formula R2=R0/n(n represents total connected decoders in whole system). Apparent deviation between measured and theoretical results means there is something wrong with communication chips for which you can find them via point-to-point exclusion method. Communication failures range can be specified by cutting off branch lines if there are many communication branch lines.