JVC VN-C655U Instructions - Page 6

Introduction Operating Precautions (continued) Ⅵ The camera incorporates an AGC circuit. As a re- Ⅵ When the camera is used to monitor the same sult, when it is used under low light conditions, the position over many hours ( e.g.continuously for 24 camera gain may increase automatically. This hours a day) the contact resistance of the panning makes the picture appear uneven , however this is mechanism may increase. This may cause the not a malfunction picture to be affected by noise interference or the Ⅵ When equipment that generates strong magnetism such as a transceiver is used near to the unit while the AGC circuit is ON, beat noise, etc may interfere with the picture. If a transceiver or similar V.Networks Controller operation becoming unstable. To prevent this happening, once a week, turn the system off and on in order to initialize the camera and to clean the contacts. equipment is used, keep it at a distance of at least Ⅵ Do not touch the lens on the dome cover directly 3 metres (10 feet) away. by hand. Contamination of the cover will lead to Ⅵ If VN-C655 and the cables connected to VN-C655 deterioration of the picture quality. are installed at a location where strong electrical Ⅵ Since the dome cover is of a hemispherical shape, or magnetic waves are generated, near a radio, the picture tends to become distorted at the edges TV set, transformer, motor etc., the quality of im- of the hemisphere. When the camera is tilted and age and color may be affected. pointed in the horizontal-direction, the picture may Ⅵ In auto iris mode, when the AGC circuit is ON, varying the iris with the iris control button may not be out of focus because the camera will then capture the edges of the hemisphere. change the picture brightness. This is due to the Ⅵ When an object is located near a light source or automatic gain boost by the V.Networks Control- contains a large difference in brightness, ghosting ler. In this case, set AGC to OFF or use the manual may occur. This phenomenon is due to the char- iris mode. acteristics of the dome cover and the built-in lens Ⅵ In auto iris mode, the V.Networks Controller may and is not a malfunction. not function under certain brightness conditions Ⅵ Make sure to use the supplied AC adaptor. (i.e. when a sufficient amount of light cannot be obtained). In this case, set the iris mode to manual. Ⅵ Certain hubs and switches equipped with SNMP functions have a broadcast or multicast control func- Ⅵ When the camera is used in ATW (Auto White bal- tion. If the function is enabled, multicast images ance) mode, the colors captured by the camera created by this product may not be viewed prop- may differ from the actual colors being shot due to erly. the mechanics of the auto-tracking operation within the white balance circuit. However, this is not a malfunction. Ⅵ Do not connect cameras other than VN-C655 to the ceiling-mounting bracket. This may cause the equipment to malfunction. Ⅵ If a very bright object (such as a lamp) is being monitored, the picture may contain vertical lines (smear) above and below the bright object in the picture. This is a normal phenomenon for solid- state image pickup devices (CCD) and is not a malfunction. 6