VCS NetCam1, Руководство пользователя

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Hardware Installation
NetCam1S, NetCam6, NetCamPlus Manual, © VCS GmbH 27
maximum cable length for RS232C interfaces is limited to around 15
m.
All serial communication parameters - number of data bits, number of stop bits, parity,
transmission speed and type of interface (where applicable) - are configurable. Con-
figuration is either accomplished locally using the supplied NCTerm terminal program
or by the ViewStation software decoder via remote control over ISDN. Local configu-
ration of the serial interface is explained in detail in chapter 6. Configured parameters
are stored in nonvolatile memory.
’Modem’-Interface
The interface port labelled ‘Modem’ for NetCam1 and NetCam6 units as well as the
single serial port featured by NetCamPlus units is mainly intended for connection to a
local modem for data transmission over analog telephone lines as well as wireless
networks such as GSM (using a GSM modem). External modems can be used if an
ISDN connection is not available or for mobile applications in the case of GSM.
Video transmission and remote control and configuration over external modems work
just like over ISDN. Due to bandwidth restrictions, especially over GSM, video quality
and/or frame rate can be compromised as compared to ISDN. Also, because of this
restriction, audio transmission has been disabled for operation with external modems.
Physical connection of external modems is accomplished using a special modem
adapter cable, available as accessory.
All modems equipped with an asynchronous interface according to RS232 resp. V.24
and compatible to the Hayes command set (AT-commands) are supported. As al-
ready mentioned, this also includes GSM-modems for wireless communication. Con-
nected modems are automatically detected and transmission speed is optimized to
the capabilities of the respective modems, regardless of the baudrate parameter con-
figured for the ’Modem’-port.
Refer to the user’s manual of the respective modem for the necessary configuration
of the modem. In most cases the default parameters or factory settings are correct for
operation with NetCam.
Both serial interfaces may also be used for connection of a local controller, e.g. a
hardware keypad or a terminal program running on a PC, like the supplied NCTerm
terminal program.
RS232C-Mode
Serial interface adhering to the RS232C standard are in wide use. Using the supplied
configuration cable, the ’Modem’-port can be directly connected to the COM-port of a