Video Microwave Digital COFDM Transmitter Model VMD-TX-X The most important thing we build is trust
how to contact COBHAM copyright notice For operator and troubleshooting information, customers are encouraged to refer to the details in this manual. For additional clarification or instruction, or to order parts, contact COBHAM. Copyright © 2005 - 2010 Customer Service is available Monday through Friday between the hours of 9:00 AM and 5:00 PM EST at: Tel: 603-880-4411 Fax: 603-880-6965 Website: www.cobham.com/dtc Email: dtc.info@cobham.
TABLE OF CONTENTS manual conventions NOTE: Describes special issues you should be aware of while using a particular function. WARNING: Calls out situations in which equipment could be damaged or a process could be incorrectly implemented, but in which operator safety is not a factor. TIP: Describes application hints.
QUICK START Complete these steps: VMD Transmitter, Front View 1 1 Connect the transmitter antenna to the SMA connector on the top of the transmitter. 2 If you plan to use audio, connect one or two microphones to the Audio 1 (A1) and/or Audio 2 (A2) connectors on the Multi-I/O cable. If using monaural, use Audio 1. 3 Connect power and video input via the Multi I/O cable: a Attach your camera video input (75 ohm composite video source in PAL or NTSC) to the Multi I/O cable BNC connector.
QUICK START 4 Set to the required configuration as indicated by the switch position. Refer to the Programming section on page 10 for more information on switch settings. Your Transmitter is now operational. Confirm its signal with your receiver. Antenna Connector NOTE: The VMD Transmitter features 16 programmable configurations (0 - 9, A - F).
INTRODUCTION VMD The VMD (Video Microwave Digital) Series of compact, low power consumption transmitters provide exceptional video quality in high multipath environments. They are ideal for use inside buildings, in urban areas, and in other applications where multipath would normally cause video tearing or breakup. All VMD Series transmitters offer three bandwidth modes: DVB-T (6, 7, 8 MHz), Narrow (2.5 MHz), and Ultra Narrow (1.25 MHz) channel spacing.
OPERATION Using your VMD Transmitter Follow the instructions given in the Quick Start section on pages 4-5. When power is first applied to the VMD, the unit reverts to the indicated channel and RF ON state. CASE TEMPERATURE: When installed with one of the two major case surfaces on an insulating surface, the case temperature will rise to approximately 40oC above ambient. With the heatsink attached, this is reduced to 30oC.
OPERATION Top and Bottom Connectors Transmitter Antenna Connector (SMA) This connector attaches to the transmitter antenna and carries the RF output signal.
PROGRAMMING System PC Controller Application Software Getting Started Advanced control of the system is available by using the PC control application software. Typically users may want to customize the default configurations to control settings such as frequency, scrambling keys, modulation parameters, and video resolution. • Use the supplied programming cable to connect the chosen COM port of your PC to the transmitter to be configured. • Launch the application by double clicking or using the Run...
PROGRAMMING Digital Video Programmer Software The opening screen of the Application Software, assuming a powered VMD unit is attached to the host computer, looks as shown (right, top). • The Unit Address is a communication parameter and is read-only. • To view and change individual configuration settings (as permitted by the Administrator) select the desired number from the scroll table on the upper left.
Transmitter Control Application PROGRAMMING RF Output This control is used to turn the RF output on and off. Turn the transmitter RF power on by selecting COFDM. Output Frequency (MHz) The Output Frequency setting allows selection of TX output frequency in increments of 0.25 MHz within the allowed tuning range of the unit. If the unit is set to a frequency that is not an integer multiple of 0.25 MHz, the unit will be automatically set to the closest frequency that is an integer multiple of 0.25MHz.
PROGRAMMING DVBT Provider Name DVB-T provider name is a place to assign a Provider name for the DVB-T configuration. DVBT Service Name DVB-T service name is a place to assign a Service name for the DVB-T configuration. DVBT FEC Rate DVB-T FEC rate selects forward error correction rates in the wideband DVB-T modes. Options are 1/2, 2/3, 3/4, 5/6, and 7/8 with 1/2 giving best range and 3/4 possibly giving better video quality under certain conditions. Recommended default is 1/2.
PROGRAMMING Narrowband FEC Narrowband FEC sets the forward error correction rate in the narrow bandwidth modes of 1.25 or 2.5 MHz. The two rates available are 1/3 and 2/3; the normal default setting for good quality video is 2/3. Changing the FEC rate to 1/3 will extend the receiver sensitivity by 2 to 3 dB at the expense of degraded video quality and longer latency. Narrowband Guard Interval Narrowband guard interval is used in the narrowband modes of 1.25 and 2.
PROGRAMMING Video Input Video input selects the video format going into the MPEG video compressor. Options are: OFF (no video input typically used when link is used for data or audio only), PAL, NTSC, NTSC no pedestal, SDI PAL, SDI NTSC. Horizontal Resolution Horizontal resolution determines the maximum number of horizontal Pixels that can be sampled by the video encoder. For optimal performance this setting should be set to the first value that exceeds the horizontal resolution of the camera in use.
Audio Encoder PROGRAMMING Audio encoder selects quantity of active audio channels (2 maximum), sampling rate (8, 16 or 32 kHz) which determines upper frequency response, and sampling bits (8 or 12) which determines audio signal to noise. (Options are listed on right.) NOTE: The higher the sampling rate, the more bandwidth required, which can increase video latency.
PROGRAMMING Serial Data (On/Off) Allows activation of the RS232 half-duplex serial data channel and selection of parity (none, even, or odd). Serial Data Baud Rate Data baud rate selects data channel baud rate, standard rates between 1200 and 115,200 baud are available. Default is 1200. Note that 57600 is not available for DVB-T modes.
PROGRAMMING TS ID Transport Stream Identifier. TS Version Number Transport Stream Version Number. PMT PID Program Map Table Packet Identifier. TS Program Number Transport Stream Program Number. PCR PID Program Clock Reference Packet Identifier. Video PID Video Packet Identifier. Video Stream ID Video Stream ID. Audio PID 1 Audio Packet Identifier Audio Stream ID Audio Stream ID. Data PID Data Packet Identifier.
SPECIFICATIONS Physical Unit Dimensions (approx.) Chassis Connector - RF Environmental Operational Temp Operational Relative Humidity Power Input Voltage Power Consumption Operating Time Control PC Control Interface Memory Video Encoding Compression Standard Line Standard Profile GOP Length Chroma Formats Video Bitrates Video Latency Audio Encoding Input Encoding Modes: Bitrates THD Response Crosstalk S/N Data Encoding Ancillary data format Composite Video Input Standards Specification Rec.
Analog Audio 2 x Microphone inputs Nominal Level Analog Audio Input Clip Level Connector Encryption Encryption type COFDM RF output RF Output Power Harmonics & Spurious RF Load Mismatch Tolerance Frequency Step Size Frequency Accuracy COFDM Standard Occupied Bandwidth DVB-T modulation Available Modulations FEC Guard Intervals COFDM Carriers Phase Noise of DVB-T OFDM carriers: Spectral Mask of DVB-T OFDM carriers: Freq offset from Cntr (MHz) ± Modulation Error Ratio Spectrum Inversion Capability Nar
CONNECTOR PIN-OUT Hirose connector: Manufacturer’s Part Number ST40X-18S-CV(80).
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TWO YEAR WARRANTY DTC Communications, Inc. (DTC) warrants its RF transmitting and receiving products to be free from defects in workmanship or material for a period of two (2) years from the date of shipment unless otherwise stated. The liability of DTC, Inc.
CONTACT US Contact Information Nashua Main Office Numbers 486 Amherst Street Nashua, New Hampshire 03063 USA (T) 603 880- 4411 (F) 603 880-6965 Toll Free in the USA 1- 800 233- 8639 Inside Sales Law Enforcement 1-800 233-8639 Military 1-800 233-8639 A complete listing of Contact Individuals can be located on our website at: www.cobham.
Cobham Surveillance 486 Amherst Street • Nashua, New Hampshire 03063 • 603-880- 4411 www.cobham.
