User Interfaces

DMD15/DMD15L IBS/IDR Satellite Modem

 

 

4.9 Modem Remote Communications

4.9.1 Host Computer Remote Communications

NOTE: This specification is applicable to the DMD15, DMD10 and DMD10L Modems. Any reference to the DMD15 in this document can be applicable to any one of these three modems.

Control and status messages are conveyed between the DMD15 and the subsidiary modems and the host computer using packetized message blocks in accordance with a proprietary communications specification. This communication is handled by the Radyne Link Level Protocol (RLLP), which serves as a protocol ‘wrapper’ for the RM&C data. Complete information on monitor and control software is contained in the following sections.

4.9.1.1 Protocol Structure

The Communications Specification (COMMSPEC) defines the interaction of computer resident Monitor and Control Software used in satellite earth station equipment such as modems, redundancy switches, multiplexers, and other ancillary support gear. Communication is bi- directional, and is normally established on one or more full-duplex 9600-baud multi-drop control buses that conform to EIA Standard RS-485.

Each piece of earth station equipment on a control bus has a unique physical address, which is assigned during station setup/configuration or prior to shipment. Valid decimal addresses on one control bus range from 032 through 255 for a total of up to 224 devices per bus. Address 255 of each control bus is usually reserved for the M&C computer.

4.9.1.2 Protocol Wrapper

The Radyne COMMSPEC is byte-oriented, with the Least Significant Bit (LSB) issued first. Each data byte is conveyed as mark/space information with two marks comprising the stop data. When the last byte of data is transmitted, a hold comprises one steady mark (the last stop bit). To begin or resume data transfer, a space (00h) substitutes this mark. This handling scheme is controlled by the hardware and is transparent to the user. A pictorial representation of the data and its surrounding overhead may be shown as follows:

S1

S2

B0

B1

B2

B3

B4

B5

B6

B7

S1

S2, etc.

The Stop Bits, S1 and S2, are each a mark. Data flow remains in a hold mode until S2 is replaced by a space. If S2 is followed by a space, it is considered a start bit for the data byte and not part of the actual data (B0 - B 7).

The COMMSPEC developed for use with the Radyne Link Level Protocol (RLLP) organizes the actual monitor and control data within a shell, or ‘protocol wrapper’, that surrounds the data. The format and structure of the COMMSPEC message exchanges are described herein. Decimal numbers have no suffix; hexadecimal numbers end with a lower case ‘h’ suffix and binary values have a lower case ‘b’ suffix. Thus, 22 = 16h = 000010110b. The principal elements of a data frame, in order of occurrence, are summarized as follows:

<SYNC>:

The message format header character, or ASCII sync

 

character, that defines the beginning of a message. The

 

<SYNC> character value is always 16h.

<BYTE COUNT>:

The Byte Count is the number of bytes in the <DATA>

 

field, ranging from 0 through 255 for the DMD5000

 

protocol (1 Byte), or ranging from 0 through 509 for the

 

DMD15 protocol (2 Bytes).

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Paradyne DMD15L operation manual Protocol Structure, Protocol Wrapper, Sync, Byte Count
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DMD15, DMD15L specifications

The Paradyne DMD15L and DMD15 are advanced digital modems designed to enhance communication in a variety of networking environments. As part of Paradyne's robust portfolio of networking solutions, these devices are engineered to deliver reliable and efficient data transmission over both copper and fiber optic connections.

One of the main features of the DMD15L and DMD15 is their capability to support Multiple Protocol Data Units (MPDUs), which enables them to handle a diverse range of network protocols seamlessly. This flexibility makes them suitable for different applications, from industrial automation to telecommunications.

These modems utilize advanced modulation techniques, such as Quadrature Amplitude Modulation (QAM), to maximize data throughput while maintaining signal integrity. This ensures that users benefit from high-speed connections, even in challenging signal environments. Furthermore, the DMD15 series incorporates Error Correction Codes (ECC) that enhance data reliability, effectively reducing packet loss and ensuring data coherence during transmission.

The DMD15L is particularly notable for its long-range capabilities, making it a go-to solution for users requiring extended distances without compromising data quality. It features built-in Adaptive Equalization, which automatically adjusts signal levels to optimize performance over varying transmission distances. This technology is crucial in maintaining consistent high-speed connectivity, especially in environments with variable conditions.

Both models are equipped with user-friendly interfaces that facilitate configuration and management. They support SNMP (Simple Network Management Protocol) for real-time network monitoring, allowing administrators to track performance metrics and identify potential issues before they impact users. The devices also include LED indicators for quick status checks, ensuring that users have immediate visibility of operational conditions.

In terms of physical characteristics, the DMD15 and DMD15L are designed for durability and ease of installation. They come in a compact form factor, making them suitable for deployment in constrained spaces. Additionally, their robust casing is built to withstand harsh environmental conditions, making them suitable for both indoor and outdoor installations.

Overall, the Paradyne DMD15L and DMD15 are high-performance modems that combine versatile technologies, reliability, and user-friendly features. They are excellent choices for organizations looking to enhance their communication capabilities and ensure robust data transmission across diverse networks. With their advanced functionalities and adaptability, these modems stand out as key components in modern network infrastructure.
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