Cirrus Logic CobraNet User Manual

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Digital Audio Networking Processor

™

CobraNet

Programmer’s Reference

CobraNet

Version 2.5

Preliminary Product Information

http://www.cirrus.com

This document contains information for a new product. Cirrus Logic reserves the right to modify this product without notice.

DS651PM25

CobraNet

Features

CobraNet

❒ Real-time Digital Audio Distribution via Ethernet ❒ No Overall Limit on Network Channel Capacity ❒ Supports Switched and Repeater Fast Ethernet Networks ❒ Fully IEEE 802.3 Ethernet Standards Compliant ❒ Fiber Optic and Gigabit Ethernet Variants Supported ❒ Ethernet infrastructure can be used simultaneously for

audio and data communications.

❒ Free CobraCAD™ Audio Network Design Tool ❒ High-quality Audio Sample Clock Delivery Over Ethernet ❒ Uncompressed 16-, 20-, and 24-bit Audio Transport ❒ Professional 48 khz and 96 kHz Sample Rate ❒ Low (1-1/3 ms) Latency ❒ Flexible Many-to-many Network Audio Routing

Capabilities

❒ Available in a family of modules and low-cost devices,

most without licensing fees or royalties.

CobraNet Interface

❒ Auto-negotiating, 100-Mbit, Full-duplex Ethernet

Connections

❒ Up to 64 Audio Channel I/O Capability ❒ Implements CobraNet protocol for real-time transport of

audio over ethernet.

❒ Local Management via 8-bit Parallel Host Port ❒ UDP/IP Network Stack with Dynamic IP Address

Assignment via BOOTP or RARP

❒ Remote Management via Simple Network Management

Protocol (SNMP)

❒ Available module form factor allows for flexible integration

into audio products.

❒ 120-MIPS Digital Signal Processor ❒ Non-volatile Storage of Configuration Parameters ❒ Safely Upgrade Firmware over Ethernet Connection ❒ LED Indicators for Ethernet Link Activity, Conductor

Status, and Fault Annunciation

❒ Watchdog Output for System Integrity Assurance ❒ Comprehensive Power-on Self Test (POST) ❒ Error and Fault Reporting and Logging Mechanisms

Host Interface

❒ 8-bit Data, 3- or 4-bit Address ❒ Virtual 24- or 32-bit Data and Addressing ❒ Polled, Interrupt, and DMA Modes of Operation ❒ Configure and Monitor CobraNet Interface ❒ Transmit and Receive Ethernet Packets at 100-Mbit Wire

Speed

Digital Audio Networking Processor

Asynchronous serial interface

❒ Full-duplex Capable ❒ 8- and 9-bit Data Formats ❒ Standard Baud Rates up to 115.2 kbps ❒ Transmitter Tri-state Control for Multi-drop Networking

Synchronous Serial audio Interface

❒ 4 Bi-directional Interfaces Supporting Up to 64 Channels

of Audio I/O

❒ 48 kHz and 96 kHz Sample Rates ❒ 64FS, 128FS, and 256FS Bit Rates Supported ❒ Supports numerous synchronous serial formats including

❒ Up to 32-bit Data Resolution

Audio clock interface

❒ 4 Host Audio Clocking Modes for Maximum Flexibility in

Digital Audio Interface Design

❒ Low-jitter, 512FS (24.576 MHz) Master Clock Oscillator ❒ Synchronize to Supplied Master and/or Sample Clock ❒ Sophisticated jitter attenuation assures network

perturbations do not affect audio performance.

Audio routing and processing

❒ Single-channel Granularity in Routing from Synchronous

Serial Audio Interface to CobraNet Network

❒ Two levels of audio routing indirection absorbs any quirks

in audio I/O interface design in host system.

❒ Local Audio Loopback and Output Duplication Capability ❒ Peak-reading Audio Metering with Ballistics

CobraNet

General Description

CobraNet is a combination of hardware (the CobraNet interface), network protocol, and firmware. CobraNet operates on a switched Ethernet network or on a dedicated Ethernet repeater network. CobraNet provides the following additional communications services for an Ethernet network.

• Isochronous Audio Data Transport

• Sample Clock Distribution

• Control and Monitoring Data Transport

The CobraNet interface performs synchronous-toisochronous and isochronous-to-synchronous

Digital Audio Networking Processor

conversions as well as the data formatting required for transporting real-time digital audio over the network.

The CobraNet interface utilizes standard Ethernet. It has the added capability to carry and utilize other Ethernet and IP compatible protocols for control and monitoring such as Simple Network Management Protocol (SNMP) and User Datagram Protocol (UDP) through the same network connection. This capability is shown below as unregulated traffic. Data communications and CobraNet applications can coexist on the same physical network in most cases.

Isochronous Data

(Audio)

Ethernet

Control Data

Figure 1. Digital Audio Distribution via Ethernet

Unregulated

Traffic

Clock

CobraNet Programmer’s Reference

Contacting Cirrus Logic Support

For all product questions and inquiries contact a Cirrus Logic Sales Representative. To find the one nearest to you go to www.cirrus.com

IMPORTANT NOTICE

Cirrus Logic, Inc. and its subsidiaries ("Cirrus") believe that the information contained in this document is accurate and reliable. However, the information is subject to change without notice and is provided "AS IS" without warranty of any kind (express or implied). Customers are advised to obtain the latest version of relevant information to verify, before placing orders, that information being relied on is current and complete. All products are sold subject to the terms and conditions of sale supplied at the time of order acknowledgment, including those pertaining to warranty, indemnification, and limitation of liability. No responsibility is assumed by Cirrus for the use of this information, including use of this information as the basis for manufacture or sale of any items, or for infringement of patents or other rights of third parties. This document is the property of Cirrus and b furnishing this information, Cirrus grants no license, express or implied under any patents, mask work rights, copyrights, trademarks, trade secrets o other intellectual property rights. Cirrus owns the copyrights associated with the information contained herein and gives consent for copies to be made of the information only for use within your organization with respect to Cirrus integrated circuits or other products of Cirrus. This consent does no extend to other copying such as copying for general distribution, advertising or promotional purposes, or for creating any work for resale.

CERTAIN APPLICATIONS USING SEMICONDUCTOR PRODUCTS MAY INVOLVE POTENTIAL RISKS OF DEATH, PERSONAL INJURY, OR SEVERE PROPERTY OR ENVIRONMENTAL DAMAGE (“CRITICAL APPLICATIONS”). CIRRUS PRODUCTS ARE NOT DESIGNED, AUTHORIZED OR WARRANTED FOR USE IN AIRCRAFT SYSTEMS, MILITARY APPLICATIONS, PRODUCTS SURGICALLY IMPLANTED INTO THE BODY,

UTOMOTIVE SAFETY OR SECURITY DEVICES, LIFE SUPPORT PRODUCTS OR OTHER CRITICAL APPLICATIONS. INCLUSION OF CIRRUS PRODUCTS IN SUCH APPLICATIONS IS UNDERSTOOD TO BE FULLY AT THE CUSTOMER’S RISK AND CIRRUS DISCLAIMS AND MAKES NO WARRANTY, EXPRESS, STATUTORY OR IMPLIED, INCLUDING THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR PARTICULAR PURPOSE, WITH REGARD TO ANY CIRRUS PRODUCT THAT IS USED IN SUCH A MANNER. IF THE CUSTOMER OR CUSTOMER’S CUSTOMER USES OR PERMITS THE USE OF CIRRUS PRODUCTS IN CRITICAL APPLICATIONS, CUSTOMER AGREES, BY SUCH USE, TO FULLY INDEMNIFY CIRRUS, ITS OFFICERS, DIRECTORS, EMPLOYEES, DISTRIBUTORS AND OTHER AGENTS FROM ANY

ND ALL LIABILITY, INCLUDING ATTORNEYS’ FEES AND COSTS, THAT MAY RESULT FROM OR ARISE IN CONNECTION WITH THESE USES.

Cirrus Logic, Cirrus, the Cirrus Logic logo designs, CobraNet, and CobraNet Silicon Series are trademarks of Cirrus Logic, Inc. All other brand and product names in this document may be trademarks or service marks of their respective owners.

CobraNet Programmer’s Reference

Table of Contents

Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

General Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

1. Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

1.1 CobraNet Terminology ........................................................................................................7

1.2 Protocol ...............................................................................................................................9

1.2.1 Beat Packet......................................................................................................... 9

1.2.2 Isochronous Data Packet (or Bundle) .................................................................9

1.2.3 Reservation Packet ............................................................................................. 9

1.2.4 Serial Bridge Packet............................................................................................ 9

1.3 Timing and Performance ................................................................................................... 10

1.4 Bundle Addressing types ..................................................................................................11

2. Control Communications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

2.1 Serial Bridge......................................................................................................................12

2.2 Packet Bridge.................................................................................................................... 13

2.2.1 Packet Bridge Buffer Data Format ....................................................................13

Processor-dependent Layout of Packet Bridge Buffers..............................13

24-bit HMI Packet Bridge Buffer Data Format ............................................14

32-bit HMI Packet Bridge Buffer Data Format ............................................14

2.2.2 Packet Bridge Receive Filtering........................................................................ 15

3. Network Stack . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

3.1 CobraNet Audio.................................................................................................................16

3.2 Serial Bridge......................................................................................................................16

3.3 Packet Bridge.................................................................................................................... 16

3.4 BOOTP..............................................................................................................................16

3.5 RARP (partial support) ......................................................................................................17

3.6 ICMP (partial support) ....................................................................................................... 17

3.7 ARP................................................................................................................................... 17

3.8 IP....................................................................................................................................... 17

3.9 UDP...................................................................................................................................18

3.10 TFTP ...............................................................................................................................18

3.11 SNMP.............................................................................................................................. 18

4. Audio Paths . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

4.1 Audio Routing Channels ...................................................................................................19

4.2 Bundle Transmitters .......................................................................................................... 20

4.3 Bundle Receivers .............................................................................................................. 20

4.4 Loopback...........................................................................................................................20

4.5 Output Channel Duplication .............................................................................................. 20

4.6 Meters ............................................................................................................................... 21

4.7 Low-latency Audio Support ............................................................................................... 21

4.8 96 kHz Sample Rate Support............................................................................................23

5. Management Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

5.1 Flash ................................................................................................................................. 25

5.2 Persistence .......................................................................................................................26

5.3 Watch Dog ........................................................................................................................26

5.4 SNMP Extension Agent..................................................................................................... 27

6. Management Interface Variable Reference. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

6.1 Legend .............................................................................................................................. 28

6.2 Data Types........................................................................................................................ 29

6.2.1 DisplayString ..................................................................................................... 29

6.2.2 OID.................................................................................................................... 29

6.2.3 IpAddress .......................................................................................................... 29

6.2.4 PhysAddress ..................................................................................................... 30

6.2.5 TimeTicks.......................................................................................................... 30

CobraNet Programmer’s Reference

Table of Contents

6.2.6 Counter .............................................................................................................31

6.2.7 Counter2 ...........................................................................................................31

6.2.8 Integer ............................................................................................................... 31

6.2.9 Integer16 ........................................................................................................... 32

6.2.10 Integer48 ......................................................................................................... 32

6.3 MIB-II Variables.................................................................................................................33

6.3.1 System .............................................................................................................. 33

6.3.2 Interface ............................................................................................................ 37

6.3.3 Address Translation .......................................................................................... 45

6.3.4 IP....................................................................................................................... 46

6.3.5 UDP................................................................................................................... 53

6.3.6 SNMP................................................................................................................ 55

6.4 CobraNet Variables........................................................................................................... 65

6.4.1 Firmware ........................................................................................................... 65

6.4.2 Hardware Identification .....................................................................................68

6.4.3 Flash .................................................................................................................69

6.4.4 Errors ................................................................................................................74

6.4.5 Conductor..........................................................................................................77

6.4.6 Conductor Information....................................................................................... 79

6.4.7 Packet Bridge....................................................................................................81

6.4.8 Serial Bridge...................................................................................................... 86

6.4.9 Interrupt Control ................................................................................................ 89

6.4.10 Audio ............................................................................................................... 92

6.4.11 Receivers ...................................................................................................... 101

6.4.12 Transmitters .................................................................................................. 105

6.4.13 Synchronization............................................................................................. 110

6.4.14 SNMP Monitor ............................................................................................... 113

6.4.15 MI Monitor ..................................................................................................... 114

6.4.16 IP Monitor ...................................................................................................... 116

6.4.17 IF Monitor ...................................................................................................... 117

6.5 DSP Extensions ..............................................................................................................119

6.5.1 Processor ........................................................................................................ 119

6.5.2 Control............................................................................................................. 120

7. Recommended User Interface Practices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122

7.1 Channel Assignments and Labeling................................................................................ 122

7.1.1 Audio I/O Map ................................................................................................. 122

7.1.2 Bundle Assignments .......................................................................................122

7.2 Conductor Priority ...........................................................................................................123

7.3 Name...............................................................................................................................123

8. Error Reporting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124

8.1 Recoverable Errors ......................................................................................................... 124

8.1.1 Receive and Transmit Errors .......................................................................... 124

8.1.2 Faults ..............................................................................................................124

8.2 Unrecoverable Errors ...................................................................................................... 124

8.2.1 Fatal Faults .....................................................................................................124

8.2.2 POST Failure ..................................................................................................125

9. Error Code Reference . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126

9.1 Legend ............................................................................................................................126

9.2 Error Code Interpretation ................................................................................................127

9.2.1 24-bit Error Code Interpretation ......................................................................127

9.2.2 32-bit Error Code Interpretation ......................................................................127

9.3 Error Codes Listing .........................................................................................................128

10. Glossary of Terms. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141

1. Overview

1.1 CobraNet Terminology

CobraNet is a technology that combines state of the art audio and communications technologies. While each have their own terminology, the following terms are used to refer to elements specific to CobraNet.

Audio Channel—A CobraNet digital audio channel operates with a sample rate 48 kHz or 96 kHz and a sample size of 16, 20, or 24 bits.

Bundle—A Bundle* is the basic CobraNet audio routing element and can carry 0 to 8 audio channels. Bundles are assigned a number which determines both which interface the Bundle is routed to and in what manner. The range within which the Bundle number falls determines whether it is routed as a multicast, unicast, or private type. Bundles are numbered 1 through 65535. CobraNet interfaces are capable of sending and receiving multiple bundles simultaneously. Bundle numbers are described in more detail in Table 2.,

"Bundle Numbering" .

Bundles were formerly referred to as channels or network channels and may be seen represented as such in some SNMP

variable names and older documentation.

CobraNet Programmer’s Reference

Overview

CobraNet Device—A CobraNet device is any equipment containing one or more CobraNet interfaces.

CobraNet Interface—The CobraNet interface is the hardware (or hardware design) and software supplied by Cirrus Logic to manufacturers of CobraNet enabled equipment. Several generations of the CobraNet interface exist and will interoperate with each other:

CS4961xx and CS1810xx - A family of CobraNet chips containing one or more 32-bit, 120-MIPS DSP cores, RAM and audio I/O circuitry.

CM-2 - A modular CobraNet interface based on a CS4961xx device.

CM-1 - A modular CobraNet interface based on a 24-bit, 100 MIPS DSP.

Silicon Series Reference Design - A CobraNet design based on the CS1810xx

or CS4961xx. This is essentially a CM-2 without the modular circuit board and host interface connector.

24-bit Platform - CobraNet interfaces based on 24-bit DSPs: Reference design, CM-1.

32-bit Platform - CobraNet interfaces based on 32-bit DSPs: CS4961xx and CS1810xx, CM-2.

Reference Design - A CobraNet interface design based on a 24-bit, 40 MIPS DSP.

Conductor—The conductor is the CobraNet interface elected to provide master clock and transmission arbitration for the network. The role of the conductor and the means for selecting a conductor are described elsewhere in this document. All CobraNet devices other than the conductor operate in a performer role.

Isochronous cycle - One or more CobraNet bundles are transmitted each isochronous cycle. The period of an isochronous cycle is 750 Hz or 1-1/3 mS

CobraNet Programmer’s Reference

Overview

Host Management Interface (HMI) - The hardware (8-bit bi-directional parallel interface) and protocol for accessing MI variables locally. The HMI is described in detail in the CS4961xx/CS1810xx Hardware Manual and CM-1 Hardware Manual.

Management Interface (MI) - The set of variables used to control and monitor the CobraNet interface. MI variables are accessible both locally through the Host

Management Interface (HMI) and over the network using Simple Network Management Protocol (SNMP). MI variables are described in detail in Section 6. "Management

Interface Variable Reference" on page 28.

Packet Bridge - A function provided by the CobraNet protocol which allows a CobraNet interface to send and receive raw Ethernet packets over the same Ethernet media used for audio transmission.

Performer - A CobraNet interface which receives its transmission permissions and master clock from a conductor. In the event a conductor fails, the CobraNet protocol will automatically promote a performer to become the new conductor.

Receiver - A logical entity within the CobraNet interface capable of receiving one Bundle.

Serial Bridge - A function provided by the CobraNet protocol which allows a CobraNet

interface to send and receive asynchronous (i.e. RS-232) data over the same Ethernet media used for audio transmission.

Transmitter - A logical entity within the CobraNet interface capable of transmitting one Bundle.

1.2 Protocol

The CobraNet protocol operates at the Data Link Layer also referred to as OSI Layer 2 or MAC layer. CobraNet uses four basic packet types described below. All CobraNet packets are identified with a unique Ethernet protocol identifier (0x8819) assigned to Cirrus Logic. As CobraNet is a Local Area Network (LAN) technology and not a Wide Area Network (WAN) technology, CobraNet does not utilize Internet Protocol (IP) to transport audio. Packet Bridge packets are generic packets and are not identified as CobraNet packets. Packet bridging is discussed in more detail in Section 2.2 "Packet Bridge" on page 13.

1.2.1 Beat Packet

A multicast packet with an address of 01:60:2B:FF:FF:00 and which contains network operating parameters, clock and transmission permissions. The beat packet is transmitted 750 times per second from a single CobraNet device on the network (the conductor) and indicates the start of the main isochronous cycle. Since the beat packet carries the clock for the network, it is sensitive to delay variation. If the delay variation specification shown in Table 1 on page 10 is not met, CobraNet devices may not be able to lock their local sample clocks to the network clock. The beat packet is typically small (on the order of 100 bytes) but can be large on a network with numerous active bundles.

CobraNet Programmer’s Reference

Overview

1.2.2 Isochronous Data Packet (or Bundle)

A multicast or unicast packet. A stream of isochronous data packets carries an audio bundle. Though the size of the packet is dependent on the number and format of the audio channels contained in the bundle, isochronous data packets are typically large. A bundle carrying 8 channels of 20-bit audio at 48kHz sample rate in the standard latency mode is approximately 1300 octets.

Isochronous data packets are transmitted in response to receipt of the beat packet. However when low-latency modes are utilized, isochronous data packets are transmitted twice or four times per isochronous cycle. The first transmission is in response to beat packet receipt, the other transmissions are made at evenly timed intervals thereafter.

Because CobraNet devices buffer isochronous data packets, out-of-order delivery of data packets is acceptable as long as the packet forwarding delay specifications in Table 1 on

page 10 are not exceeded.

1.2.3 Reservation Packet

A multicast packet with an address of 01:60:2B:FF:FF:01 used by the CobraNet protocol to allocate bandwidth and establish connections between CobraNet interfaces. CobraNet devices transmit reservation packes as needed or typically once per second at minimum.

1.2.4 Serial Bridge Packet

A multicast or unicast packet used to bridge asynchronous serial data between CobraNet interfaces. Serial bridging is discussed in more detail in Section 2.1 "Serial Bridge" on

page 12.

CobraNet Programmer’s Reference

Overview

1.3 Timing and Performance

CobraNet provides real-time audio delivery and requires real-time performance from the network on which it is deployed. The best means of insuring a network will deliver the performance required by CobraNet is to verify the design using Cirrus Logic’s CobraCAD CobraNet modeling software (available for download at www.cirrus.com). The design check feature in CobraCAD assures that the performance requirements shown in Table 1 are met and that the network is capable of delivering the bandwidth required to support the modeled application.

Table 1. Network Performance Requirements

Parameter Maximum Comments

Beat Packet Delay Variation 250µs

If delivery of beat packets periodically varies from the nominal delay by more than this value, then the Receivers may loose sample lock or fail to meet clock delivery specifications.

Forwarding Delay, 5-1/3ms latency

Forwarding Delay, 2-2/3ms latency

Forwarding Delay,

1-1/3ms latency

Maximum Forwarding Delay 5000µs Audio cannot be delivered at any latency with extreme forwarding delays.

Maximum Forwarding Delay Variation, 5-1/3ms latency

Maximum Forwarding Delay Variation, 2-2/3ms latency

Maximum Forwarding Delay Variation, 1-1/3ms latency

a. Store-forward delay on a 100Mbit Ethernet connection is 121us (assuming maximum length packets). This forwarding

delay specification is only achievable on an audio-only dedicated network. The lowest latency achievable with CobraNet on a non-dedicated network is 1-2/3ms (using the 1-1/3ms latency mode with an rxMinDelay setting of 0x40 to make receivers tolerant to queuing delays introduced by non-audio traffic).

500µs

250µs

125µs

1000µs

500µs

250µs

Forwarding delay is the sum of store forward, queuing and propagation delays. Forwarding delay includes delay variation - i.e. 150µs forwarding delay + 250µs delay variation = 400µs. Thus tolerance of forwarding delay is reduced in the presence of delay variation. When forwarding specification is exceeded, audio is delivered reliably with additional latency. rxDelay and rxMinDelay can be used to observe and control this adaptation to forwarding delay.

Delay variation exceeding these specifications will result in unreliable audio transport due unstable rxDelay determination. In some cases this may be addressed through manual rxMinDelay setting.

1.4 Bundle Addressing types

Multicast bundles represent a least common denominator for audio interoperability in

CobraNet networks. Bundles sent with multicast destination addresses are delivered indiscriminately to all CobraNet interfaces and thus have the potential of overloading a network. Care should be taken to insure that an excessive number of multicast bundles are not used. See Bundle Assignments in CobraNet Systems (available for download at

www.cirrus.com

Unicast bundles are sent to only one destination on a network. However, in the event that more than one CobraNet interface is set to receive the same bundle number, the CobraNet protocol may, according to rules governed by the txUniCastMode and txMaxUnicast variables, cause unicast bundles to be sent as multicast or multi-unicast when necessary. Multi-unicast will use unicast addressing to send up to four copies of the same bundle to different CobraNet interfaces.The default configuration for txUnicastMode insures that unicast bundles are never multicast.

Private bundles are a special case of unicast or multicast bundles. The transmitter's MAC address, in addition to the bundle number, is required to fully qualify a private channel at the receiver. Like unicast bundles, these may be either unicast or multicast based on txUnicastMode.

) for a discussion of issues associated with multicast bundles.

CobraNet Programmer’s Reference

Overview

Note: Transmitted bundles must have a unique bundle number assigned to them. More than one transmitting interface cannot use the same bundle number. Multiple receiving interfaces can receive the same bundles.

Hexadecimal

Bundle

Number

0 0 Null

1-0xFF 1-255 Multicast

0x100-

0xFEFF

0xFF00-

0xFFFF

Decimal

Bundle Number

256-65279 Unicast

65280-65535 Private

Designation Usage

Table 2. Bundle Numbering

Unused bundle. Disables transmission/reception when selected.

Transmitted by a single CobraNet interface and received by any number of interfaces.

Transmitted by a single CobraNet interface. Dependent on txUnicastMode and txMaxUnicast settings may be received at a single (default case), a few (multiple unicast case) or a large number (multicast case) of interfaces.

Individual transmitters locally allocate private channels. The bundle number is conditioned on the transmitter's MAC address. There are 256 of these bundles per transmitter thus the total number of private bundles is virtually unlimited as the bundle numbers are unique to a particular MAC address.

Transmission

Addressing

Never transmitted. Never transmitted.

Always multicast

Generally unicast but may multicast if txUnicastMode variable is adjusted.

Transmission

Mode

Always transmitted.

Only transmitted when at least one receiver is identified via reverse reservation.

CobraNet Programmer’s Reference

Control Communications

2. Control Communications

2.1 Serial Bridge

Asynchronous serial data may be bridged across the network using the serial bridge hardware and software. The CobraNet interface has a two wire logic-level asynchronous interface. Characters received on the interface are buffered and placed in the payload of a special serial bridge Ethernet packet. The packet is then transmitted onto the network with unicast or multicast addressing as configured. It is received at the destination CobraNet interface where the data in the packet is re-serialized and presented on the serial interface. Many standard asynchronous serial formats are supported. With proper physical interface circuitry, this port can be made to support RS-232, RS-422 or RS-485 standards. Multi-drop two-wire interfaces are also supported.

The bridging feature can be useful in a CobraNet product as either an internal or external control interface. Used externally, the appropriate transceiver, such as an RS-232 driver chip, is connected to the logic-level pins and in turn connected to a standard connector, such as a DB-9 or DB-25, on the back panel. This allows control of external serial interfaced devices remotely over Ethernet.

RS-485 Multi-drop

CobraNet

Interface

etwork

Figure 2. Serial Bridging, External Application

Ethernet Network

CobraNet

Interface

RS-232 Connection

Internal application of the serial bridge allows serial communications over the network between host processors which are incorporated into CobraNet devices. Using this communication scheme reduces engineering effort in integrating CobraNet into audio products that already accomplish control communications via serial link.

Micro-

controller

CobraNet

Interface

Ethernet Network

CobraNet

Interface

Micro-

controller

Figure 3. Serial Bridging, Internal Application

Although the serial bridging feature strives to transmit data at wire speed, delays are introduced by the process of serializing, de-serializing, and prioritizing the serial bridge packets. These delays are typically on the order of 10ms or less.

See Table 6.4.8 on page 86 for details on the MI variables used to control serial bridging.

2.2 Packet Bridge

The packet bridge provides a means for using the CobraNet interface as if it were an Ethernet controller by providing a basic capability to send and receive raw Ethernet packets. A CobraNet device utilizing a host processor with network stack can use this feature to transmit and receive both control and audio data over the same network connection.

In the simplest implementation, the host sees the packet bridge as several control variables, a receive buffer, and a transmit buffer which are accessed via the HMI interface. Ethernet data packets are transferred in both directions over the host port using the same HMI semantics used to read and write other MI variables.

More advanced implementations can take advantage of interrupt and DMA modes of HMI operation as well as some HMI operations specifically tailored to packet bridge functions.

CobraNet Programmer’s Reference

Control Communications

Refer to Table 6.4.7 on page 81 for details on the MI variables used to control packet bridging.

2.2.1 Packet Bridge Buffer Data Format

Packets are transmitted by writing raw packet data to bridgeTxPktBuffer. Packets are received by reading bridgeRxPktBuffer. Data in both buffers shares the same format. The first word of the buffer specifies the byte length of the data that follows. Byte length includes the14-byte Ethernet header. The Frame Check Sequence (FCS) is automatically appended to transmitted packets and automatically checked and stripped from received packets. The FCS is not included in the packet data or byte length specification. Byte length should be in the range 14 to 1514.

2.2.1.1. Processor-dependent Layout of Packet Bridge Buffers

Refer to Ta bl e 3 and Table 4 on page 14 for organization of data within bridge buffers for 24- and 32-bit platforms. All data marked as unused/0 will be received as 0 and must be set to 0 when writing the buffer prior to transmission.

For both platforms, requested transmissions shorter than the 60-byte Ethernet packet minimum will be padded to 60 bytes with indeterminate data.

CobraNet Programmer’s Reference

Control Communications

Table 3. Packet Bridge Buffer Layout, 24-bit Platforms

MS Middle LS

Word 1

Word 2

Word 3

Word 4

Word 5

Word 6

Word 7

Word 8

Word n

Packet byte length MS Packet byte length LS unused/0

Destination MAC byte 2 Destination MAC byte 3 unused/0

Destination MAC byte 4 Destination MAC byte 3 unused/0

Destination MAC byte 6 Destination MAC byte 5 unused/0

Source MAC byte 2 Source MAC byte 1 unused/0

Source MAC byte 4 Source MAC byte 3 unused/0

Source MAC byte 6 Source MAC byte 5 unused/0

Protocol identifier LS Protocol identifier MS unused/0

Payload byte 2 Payload byte 1 unused/0

...

Payload byte n Payload byte n-1 unused/0

... ... unused/0

2.2.1.2. 24-bit HMI Packet Bridge Buffer Data Format

Packet byte length is specified in the two MS bytes of the first word. The LS bytes will read 0 on receipt and must be set to 0 for transmit. Transmit byte length is rounded up to the nearest even multiple of 4. Receive byte length indicates the actual number of bytes received.

2.2.1.3. 32-bit HMI Packet Bridge Buffer Data Format

Packet data begins with the second word. Transmission order of each word is MH, MS, LS, ML.

Table 4. Packet Bridge Buffer Layout, 32-bit Platforms

MS MH ML LS

Word 1

Word 2

Word 3

Word 4

Word 5

Word 6

Word n

Byte length MS Byte length LS unused/0 unused/0

Destination MAC byte 2 Destination MAC byte 1 Destination MAC byte 4 Destination MAC byte 3

Destination MAC byte 6 Destination MAC byte 5 Source MAC byte 1 Source MAC byte 2

Source MAC byte 4 Source MAC byte 3 Source MAC byte 6 Source MAC byte 5

Protocol identifier LS Protocol identifier MS Payload byte 2 Payload byte 1

Payload byte 4 Payload byte 3 Payload byte 6 Payload byte 5

...

Payload byte n-2 Payload byte n-3 Payload byte n Payload byte n-1

... ... ... ...

2.2.2 Packet Bridge Receive Filtering

The packet bridge can allow only selected packets to be passed to the bridge buffer or allow copies of packets to be sent to the bridge buffer. The value of the bridgeRxFilter variable controls the filter mode. With bridgeRxFilter = 0x10 or 0x01 the packet bridge sends selected packets of unknown protocol to the HMI interface via the packet bridge buffer. With bridgeRxFilter = 0x02 or 0x08, copies of selected packets are passed both to the packet bridge and are processed by the CobraNet interface. The packet bridge never passes audio data packets or beat packets to the host. The operation of packet bridge filtering is shown in Figure 4 below.

Ethernet

Packet

CobraNet Programmer’s Reference

Control Communications

0x10 Bridges all Packets with

Unknown Protocol

(Usually Custom Control Protocol)

CobraNet?

0x8819

Reservation

Request?

Beat

Packet?

Serial Bridge

Packet?

Audio

Bundle?

N=Special

Case

Process

Reservation

Request

Process

Beat Packet

Process

Serial Bridge

Packet

Process

Audio Bundle

0x08 Copies all IP Packets and Forwards to Host Processor

ARP/RARP?

Process

ARP or RARP

Request

IP?

Packet

DestinationIP=

ipMonCurrentIP?

SNMP?

TFTP?

BOOTP?

Packet Dropped

SNMP Agent

TFTP Server

BOOTP Client

Process

Packet Bridge

RxPktBuffer

0x02 Copies Reservation Requests and Forwards to Host Processor

0x01 Bridges Special 0x8819 non-audio Packets

Figure 4. Packet Bridge Receive Filtering

The default value of BridgeRxFilter is 0x01. When BridgeRxFilter is set to 0x08 and/or 0x02, the CobraNet interface and the host processor can independently process the same packets. The Host processor can use 0x08 in order to respond to packets with IP addresses other than the address assigned to the CobraNet interface. Care must be taken in the host processor software when using these modes to ensure that the CobraNet interface and Host Processor do not both respond to the same packets.

CobraNet Programmer’s Reference

Network Stack

3. Network Stack

CobraNet ServicesInternet Protocol Suite

Applicatio

Transport

Network

Logical Link

Physica

3.1 CobraNet Audio

This includes transmission and reception of audio data packets and reservation requests, implementation of conductor arbitration, and the ability to serve in either conductor or performer roles. CobraNet audio is a self-contained service that spans from Logical Link (2) to Application (7) layers.

3.2 Serial Bridge

This service provides bridging of asynchronous serial streams over the Ethernet network. This self-contained service spans from the logical link to the Application layer. The serial bridge service is discussed in Section 2.1 "Serial Bridge" on page 12.

BOOTP SNMP TFTP

UDP

ICMP

Figure 5. CobraNet Network Stack

IP RARP ARP

802.3 Ethernet

Fast Ethernet Inter face

CobraNet

Audio

Serial

Bridge

Packet Bridge

3.3 Packet Bridge

This service simply allows the CobraNet interface to operate as an Ethernet controller for a connected host. This service works at the logical link layer and provides access to the network without providing any actual network services. The packet bridge feature is discussed in Section 2.2 "Packet Bridge" on page 13.

3.4 BOOTP

The boot protocol (BOOTP) is supported as specified in RFCs 951 and 1542. Network clients use BOOTP to receive an IP address from a BOOTP server.

Clients needing an IP address will broadcast a BOOTP request packet. A BOOTP server on the network will respond with a BOOTP response containing the preferred IP address for the client to use. Use of BOOTP simplifies the error-prone task of assigning unique IP addresses to devices on a large network. BOOTP is carried via UDP/IP and, as such, is able to pass through properly configured routers.

BOOTP requests are transmitted by the CobraNet interface on a randomized schedule as recommended in the RFCs. Requests are sent out frequently at startup and then taper

down to an approximate 2-per-minute minimum rate. Two conditions must be met before a CobraNet device will send out BOOTP requests:

• The device must not already have an IP address. Apart from BOOTP, there are two other means for a CobraNet interface to obtain an IP address - RARP and the ipMonitor variables.

• The device must be attached to a switched network. In order to avoid producing unregulated traffic, BOOTP requests are not transmitted on a repeater network.

Upon receipt of a valid BOOTP response, a CobraNet device will change its IP address to the IP address indicated by the BOOTP response. It is not necessary for a response to be paired with a specific request to be considered valid.

3.5 RARP (partial support)

RFC 903 defines reverse address resolution protocol (RARP). Network clients use RARP to receive an IP address from a central server. RARP differs from BOOTP in that it is carried at the logical link layer (Layer 2) and thus cannot pass through IP routers.

RARP is comprised of request and response packet types. Upon receipt of a valid RARP response packet, a CobraNet device will change its IP address to the IP address indicated by the RARP response. The CobraNet network stack does not transmit RARP request packets.

CobraNet Programmer’s Reference

Network Stack

RARP is the means used by the CobraNet Discovery application (Disco) and CNDisco object for IP address assignment.

3.6 ICMP (partial support)

Internet control message protocol (ICMP) is an administrative protocol defined in RFC

972.

CobraNet devices which have been assigned an IP address will respond to ICMP echo (commonly referred to as ‘ping’) requests. No other ICMP support is implemented in the CobraNet network stack.

3.7 ARP

Address resolution protocol (ARP) is used by the IP protocol to translate IP addresses to MAC addresses according to RFC 826.

A host seeking a MAC address associated with an IP address broadcasts an ARP request. The device using the specified IP address replies with an ARP response packet. In this way the requesting host obtains the MAC address for the target device.

The CobraNet interface responds to ARP requests when appropriate. CobraNet will not generate ARP requests. For this reason the CobraNet can only respond to IP messages and cannot initiate IP communications.

3.8 IP

The internet protocol (IP) is defined in RFC 791. IP is a network protocol (layer 3 of the OSI 7-layer networking model) responsible for routing of packets and segmentation and reassembly of packets.

CobraNet Programmer’s Reference

Network Stack

The CobraNet implementation of IP has the following limitations:

• Segmentation and reassembly is not supported. Segmentation is primarily utilized by stream based TCP protocols that can generate large data packets. Reassembly capability can be necessary on heterogeneous networks (those comprising multiple network technologies such as Ethernet, FDDI, and ISDN).

• Cannot initiate IP communications; can only respond to incoming messages. The CobraNet implementation does not support net mask and default gateway concepts required to initiate communications to other subnets. Furthermore, CobraNet's implementation of ARP does not support generation of ARP requests.

3.9 UDP

User datagram protocol (UDP) is defined in RFC 768. UDP is a transport protocol (layer 4 of the OSI 7-layer networking model) responsible for maintaining the integrity of data. UDP is an extremely simple protocol which, by design, defers the data integrity problem to application protocols in higher network layers.

CobraNet fully supports UDP.

3.10 TFTP

3.11 SNMP

Trivial file transfer protocol (TFTP) is defined in RFC 783. TFTP supports file read and write via a UDP/IP transport. The CobraNet implementation of TFTP supports only binary reads and writes to a specific set of files. This is the mechanism used to update firmware in a CobraNet interface. The TFTP file names correspond to the different sectors of the FLASH memory and can differ in name and size for different revisions of CobraNet interface hardware.

Firmware update is a complex process best accomplished by use of an encapsulated software module, such as the PACNFirm object library, or by use of the CobraNet Discovery program which are aware of the data structures and protocol utilized.

Version 1 of the simple network management protocol (SNMP) is defined in RFC 1157. The CobraNet SNMP interface is version 1 compliant.

A management information base (MIB) is associated with any SNMP implementation. CobraNet supports the standard MIB for network devices as defined in RFC 1213 “MIB-II” in addition to its own MIB for CobraNet-specific objects.

The CobraNet MIB file is available for public download in order to facilitate full use of the CobraNet SNMP interface via SNMPv1 compliant applications.

4. Audio Paths

CobraNet Programmer’s Reference

Audio Paths

Synchronous

Serial Receivers

RX1

RX2

RX3

RX4

Up to 8 Channels Each

TX1

TX2

TX3

TX4

Up to 8 Channels Each

Synchronous Serial

Transmitters

Audio Buffering

Audio Routing

Channels

0 (Silence)

audioMap

Ethernet

32 33

Transmitters

TxSubMap

Dup Variables

RxSubMap

Receivers

audioLoopSrc

audioDupSrcaudioDupDst

Loop Variables

audioLoopDst

Outgoing

Audio Bundles

Audio Output Metering

audioMeterMap

Audio Input Metering

Incoming

Audio Bundles

Ethernet

NOTES: 1. Do not alter audioMap, use txSubMap and rxSubMap to control routing to/from Bundles and SSI.

2. The number of transmitters and receivers may vary depending on the implementation.

Figure 6. CobraNet Interface Audio Model

4.1 Audio Routing Channels

There are 65 audio routing channels within a CobraNet interface numbered from 0 to 64. Channels 1 through 32 are used to route audio from the Synchronous Serial Interface (SSI) to the network transmitters. Channels 33 through 64 are used to route audio from

CobraNet Programmer’s Reference

Audio Paths

the network receivers to the SSI outputs. Routing channel 0 is a special logical channel used to supply silence to a transmitted channel or serve as a “bit bucket” when receiving from the network.

Audio arrives and leaves the interface through the SSI receivers and transmitters. As each sample arrives it is buffered. The mapping of audio input and output channels to audio I/O buffer offsets is fixed (and non-intuitive). To accommodate channel numbering differences of different CobraNet devices, the audioMap variables allow a mapping from audio I/O buffer offsets to routing channel numbers. This mapping is preset by the manufacturer and should never need to be altered.

4.2 Bundle Transmitters

A Transmitter is a logical entity within the CobraNet interface capable of transmitting one bundle of up to 8 audio channels. Input audio routing channels (0, 1 through 32) are mapped into Bundles associated with a particular transmitter via the txSubMap variables associated with that transmitter. There are 8 txSubmap variables associated with each transmitter, each of which can be set to a particular routing channel number. The first txSubMap variable sets the routing channel that will be transmitted in the first audio channel in the bundle. The second txSubmap variable selects the source for the second audio channel to be transmitted in the bundle...and so on.

Audio resolution (sample size) and sample rate (48 kHz or 96 kHz) are determined by other transmitter parameters discussed in this document.

4.3 Bundle Receivers

A Receiver is a logical entity within the CobraNet interface capable of receiving one bundle of up to 8 audio channels. Output audio routing channels (0, 33 through 64) are mapped from the receiver via the rxSubMap variables. There are 8 rxSubMap variables associated with each receiver, each of which can be set to a particular routing channel number. The first rxSubMap variable selects the routing channel that will receive the first audio channel in the bundle. The second rxSubMap variable specifies mapping the second audio channel in the bundle...and so on.

4.4 Loopback

The loopback object provides a means for the interface to transfer audio channels internally. Loopback overcomes the limitation that a device cannot receive its own transmission and also allows the audio I/O system to be tested locally.

The audioLoopSource and audioLoopDest variables control this feature.

4.5 Output Channel Duplication

The audio routing channel mapping facilities allow a single routing channel to be mapped to any number of audio channels in any number of network transmitters (Bundles). It is, however, not possible to direct an audio channel in a network receiver to multiple audio routing channels for output through multiple SSI channels or ports.

Output channel duplication allows output routing channels to be copied to other output routing channels. This feature is implemented as a separate set of “dup” paths controlled

by audioDupSource and audioDupDest variables. An output can be specified as the source for a duplication by multiple “dup” paths. Output duplication is accomplished without incurring additional audio latency. See Section 6.4.10 "Audio" on page 92 for more information.

4.6 Meters

Metering is provided for all 64 audio routing channels. The first 32 meters can be mapped to the 32 input routing channels. The second 32 meters are used to meter the output routing channels. Mapping is controlled by the audioMeterMap variable

Metering is disabled by default to conserve processing cycles. Meters are peak detecting with simple first-order decay ballistics. Ballistics are comprised of an instantaneous attack and exponential decay time programmable via audioMeterDecay variable. Ballistics are adjusted globally for all meters. All level measurements are peak level (as opposed to RMS, for instance). Level is indicated in 24-or 32-bit positive signed values. A cumulative peak hold element on each meter allows accurate detection of any clipping condition. See

Section 6.4.10 "Audio" on page 92 for more information.

4.7 Low-latency Audio Support

CobraNet Programmer’s Reference

Audio Paths

Low-latency modes are supported on CobraNet interfaces without need for hardware changes to the CobraNet interface or CobraNet Device. The default mode of operation is 5-1/3 mS latency at 48 kHz sample rate.

Running in low-latency mode requires more processing power, implying a trade-off between the number of channels supported and reduction of latency. Some referencedesign-based products need to operate at reduced channel count to support lower latency. Depending on selected sample size, sample rate, and latency, newer CobraNet interfaces may be subject to some limitation in channel capacity, number of transmitters and receivers, and multiple unicast transmission count.

The following table shows CM-1 channel capacity for several latency and sample rate operating modes. Eight-channel bundles with 20-bit resolution, unicast to a single destination or multicast is assumed.

Low-latency modes also place additional demands on network performance. Specifically, in order to achieve the desired latency, forwarding delay across the network needs to be reduced by approximately the same factor that audio latency is reduced. These requirements bring into play new network design rules.

Lower latency is achieved by transmitting smaller audio packets at a higher rate. A restriction on the number of audio channels allowed in a bundle is due to a restriction on

CobraNet Programmer’s Reference

Audio Paths

the maximum size of an Ethernet packet. Therefore Lower-latency modes have relaxed restrictions in this area. Audio channel count restrictions are summarized below.

Table 5. Bundle Capacity Limits as a Function of Ethernet Packet Size

Latency

16 bit, 48 kHz 20 bit, 48 kHz 24 bit, 48 kHz 16 bit, 96 kHz 20 bit, 96 kHz 24 bit, 96 kHz

5-1/3 ms 8 8 7 5 4 3

2-2/3ms 888887

1-1/3ms 888888

Bundle capacity or maximum channel count may be limited in some cases by both the allowable Ethernet packet size and by the processor bandwidth required to handle lower latency and/or higher sample rate modes. Limitations imposed by packet size are illustrated in Ta bl e 5 . Limitations imposed by additional bandwidth requirements are discussed in the Hardware Reference Manual applicable to the particular CobraNet Interface.

Channels per Bundle

CobraNet Programmer’s Reference

Audio Paths

A CobraNet interface operates at a single latency and sample rate mode as specified by the modeRateControl variable. This latency mode applies to all incoming and outgoing audio at the interface.

Table 6. txSubFormat and rxSubFormat1 Values

txSubFormat Value Resolution Sample Rate Latency

0 No Signal

0x044000 16 bit 48 kHz 5-1/3 ms

0x054000 20 bit 48 kHz 5-1/3 ms

0x064000 24 bit 48 kHz 5-1/3 ms

0x148000 16 bit 96 kHz 5-1/3 ms

0x158000 20 bit 96 kHz 5-1/3 ms

0x168000 24 bit 96 kHz 5-1/3 ms

0x042000 16 bit 48 kHz 2-2/3 ms

0x052000 20 bit 48 kHz 2-2/3 ms

0x062000 24 bit 48 kHz 2-2/3 ms

0x144000 16 bit 96 kHz 2-2/3 ms

0x154000 20 bit 96 kHz 2-2/3 ms

0x164000 24 bit 96 kHz 2-2/3 ms

0x041000 16 bit 48 kHz 1-1/3 ms

0x051000 20 bit 48 kHz 1-1/3 ms

0x061000 24 bit 48 kHz 1-1/3 ms

0x142000 16 bit 96 kHz 1-1/3 ms

0x152000 20 bit 96 kHz 1-1/3 ms

0x162000 24 bit 96 kHz 1-1/3 ms

rxSubFormat is a read only variable indicating the format of the audio data being received and decoded. It will have the same value as txSubFormat with the exception of the least-significant bit. i.e. 16-bit, 48 kHz sample rate, 5 1/3-mS latency = 0x44001 when the data is being successfully decoded.

modeRateControl must also be set to the correct value necessary to support the mode selected by txSubFormat.

4.8 96 kHz Sample Rate Support

A CobraNet interface may operate at either 48 kHz or 96 kHz but not both rates simultaneously. A device operating at 48 kHz cannot receive audio from a device operating at 96 kHz and vice versa. However, CobraNet interfaces operating at 96 kHz and 48 kHz audio may co-exist on the same network.

CS4961xx, CS1810xx, CM-2, and CM-1 based interfaces are required for 96 kHz sample rate operation. No hardware changes are required to support the increased sample rate on these platforms. 96 kHz is not supported in the legacy CobraNet Reference Design.

CobraNet Programmer’s Reference

Audio Paths

Sample rate is selected by the modeRateControl variable. modeRateControl selects both sample rate and audio latency. 96 kHz sample rate and low-latency modes can be used together.

rxSubFormat indicates the type and status of audio date being received. The LS bit of this variable indicates whether data in the sub channel is being decoded. A value of 0 indicates inability of the interface to decode the received data. An interface operating at 48 kHz cannot decode 96 kHz audio. An interface operating at 96 kHz cannot decode 48 kHz audio.

Processing 96 kHz audio requires twice the bandwidth. At 5-1/3 ms latency, all of the data is transmitted in one packet and thus the number of channels that can be transferred per bundle may be reduced. Lower latency modes can support more channels at 96 kHz, as the data is distributed across 4 packets at 1-1/3 mS and 2 packets at 2-2/3 ms latency. See Table 5., "Bundle Capacity Limits as a Function of Ethernet Packet Size" for more detail on this topic.

When operating in 96 kHz mode, the Master Clock remains at the standard 24.576 MHz. However, in 96 kHz mode, the Sample Clock Output (FS1) will change to support a 96 kHz signal. If a sample clock cascade and/or reference clock input is supplied, this signal may be either 48 kHz or 96 kHz in 96 kHz mode but must be 48 kHz in 48 kHz mode.

Table 7. Bit Clock Rates

Synchronous Serial Port Operating Mode 48 kHz SCK Rate 96 kHz SCK Rate

64Fs (2 channels x 4 interfaces) 3.072 MHz 6.144 MHz

128Fs (4 channels x 4 interfaces) 6.144 MHz 12.288 MHz

256Fs (8 channels x 4 interfaces) 12.288 MHz 24.576 MHz

5. Management Interface

The Management Interface (MI) is the means by which the CobraNet interface is controlled and monitored. Integral to the management interface are the MI variables. The MI variables are read and written via the Host Management Interface (HMI) or remotely over the audio network via SNMP. Both methods operate on the same common set of MI variables. The CobraNet device is configured in real time as the variables are changed.

Variables may have read-only, read/write, or read/write-persistent attributes. All variables are given an initial value at startup. The value of all variables can be read. Read/write and Read/write-persistent variable types can be both read and written. The value of persistent variables is saved in flash memory and the variable is restored at startup to the last value written. See Section 5.2 "Persistence" on page 26 for more detail on persistent variables. All MI variables are documented in the Section 6. "Management Interface Variable

Reference" on page 28.

MI variables fall into three classes. CobraNet-specific variables allow for configuration and monitoring of CobraNet functionality such as audio transmission and reception. A second class of variables known as SNMP MIB-II variables provides a uniform means of monitoring a network device. These variables are primarily concerned with performance and configuration of the network interface and associated protocols. A third class of product-specific variables may exist when a manufacturer makes use of SNMP extension agent capabilities. This third class of variables is used for controlling and monitoring product-specific features and functions.

CobraNet Programmer’s Reference

Management Interface

5.1 Flash

Flash memory may be updated via TFTP or through HMI. The HMI flash memory access mechanism allows flash contents to be read and written via the host port. This provides functionality for the HMI similar to that which TFTP provides via the network.

The mechanism cannot allow direct access to the flash memory. Instead a request to read or write flash is performed by supplying the flash address (flashTAddress), byte length (flashTLength), transfer direction (flashTDirection), and data (bridgeTxPktBuffer). The request is then initiated by writing to flashTRequest.

The flash memory is a byte-wide device. On 24-bit CobraNet platforms, the transmit buffer is comprised of 3-byte words. The mapping between the byte-wide flash data and the wider buffer memory is as follows.

Table 8. Flash Layout, 24-bit Platforms

MS Middle LS

First Word

Second Word

Byte 3 Byte 2 Byte 1

Byte 6 Byte 5 Byte 4

CobraNet Programmer’s Reference

Management Interface

On 32-bit CobraNet platforms, the transmit buffer is comprised of 4-byte words. The mapping between the byte-wide flash data and the wider buffer memory is as follows.

Table 9. Flash Layout, 32-bit Platforms

MS MH ML LS

5.2 Persistence

The persistence feature causes values written to Read/write-persistent type variables to be written to flash and for these stored values to be restored during startup. With the persistence feature disabled, Read/write and Read/write-persistent variables behave identically. Persistence is enabled by setting the flashPersistEnable variable.

With persistence enabled, values written to Read/write-persistent variables are written to flash by a background task according to a schedule designed to prevent excessive write cycles on the memory and to avoid interference with other critical functions. In extreme cases it can take up to 1 minute to store changed values. However, the persistence feature is implemented such that it is safe to remove power at any time with the caveat that the values recalled may not include changes made immediately prior to removal of power. Variable values will never become corrupted due to unexpected loss of power or network connection.

flashPersistAck can be used to ensure that variables have been stored to non-volatile memory prior to removal of power.

First Word

Second Word

Byte 4Byte 3Byte 2Byte 1

Byte 8Byte 7Byte 6Byte 5

5.3 Watch Dog

The watch dog is a digital signal from the CobraNet interface provided to allow fault detection. The watch dog signal is toggled periodically by firmware to indicate normal operation. The toggle rate may drop to as low as 5 Hz on occasion, depending on processor load. Actual minimum, maximum, and nominal toggle rates can be found in the Hardware Reference Manual applicable to the particular CobraNet interface.The watch dog signal will stop toggling following detection and reporting of a fatal error condition. The interface should be reset and re-initialized when absence of the watchdog signal is detected.

Use of the watchdog requires external hardware and/or software. A hardware solution may be implemented with a “microprocessor manager” chip such as the DS1236 from Dallas/Maxim. A software solution could involve wiring the watch dog signal to an I/O port, timer, or interrupt on the host processor and then wiring the CobraNet reset signal to a general purpose output. Software on the host processor would monitor the interval between watch dog transitions and assert the reset signal if the interval exceeds the maximum period.

Implementation of the watch dog feature is not mandatory but is recommended. ESD, EMI, and power fluctuation events are not uncommon in audio installations and the ability to survive and recover from such conditions is a prerequisite for passing many electrical certification programs.

5.4 SNMP Extension Agent

CobraNet’s SNMP agent feature allows the CobraNet interface to be monitored and configured over the Ethernet network by an SNMP manager (or managers). An enhancement of this capability is the SNMP extension agent which allows these monitoring and control capabilities to be extended to product-specific features and functionality.

SNMP extensions require use of a host processor attached to the CobraNet interface. The extension agent appears to the processor as additional product-specific variables in the HMI memory space. For status reporting, the host microcontroller writes updated values to the associated HMI locations. SNMP requests can then be used to read these values at any time. Extension values can also be written via SNMP and monitored by the host processor in order to provide a control path to the host processor via SNMP.

Extensions implemented along with the appropriate hardware and host software can be used to control and monitor many useful functions. For example, extension variables can be used to remotely monitor metrics such as gain, clipping and temperature. They can also be used to control functions such as gain, noise gates, and compression. The system will also benefit from the persistence feature, allowing settings for the entire product, not just the CobraNet interface, to be retained through a power-cycle.

CobraNet Programmer’s Reference

Management Interface

By using the extension agent, the entire product may be made SNMP manageable without need for the host processor to be burdened with the complexity of running a network stack and SNMP agent.

CobraNet Programmer’s Reference

Management Interface Variable Reference

6. Management Interface Variable Reference

CobraNet interfaces are configured and monitored by reading and writing Management Interface variables. MI variables may be accessed directly via a processor attached to the Host Management Interface or via the network using SNMP. The method of using the HMI is similar for all CobraNet interfaces but may require specific semantics and may have different word sizes depending on the actual implementation. The HMI interface is described in more detail in the Hardware Reference Manual applicable to the particular CobraNet Interface. Following are detailed descriptions of the size, contents, and effects of the MI variables as well as their HMI addresses and SNMP Object Identifier numbers. All MI variables can be accessed via the HMI but some variable properties render them inappropriate for accessing via SNMP. These exceptions are noted in the variable descriptions where applicable.

6.1 Legend

Name - Name of variable as seen in CobraNet MIB and cobrami.h header file.

Description - Description of the variable including allowed values and usage discussion.

Host Address - HMI addresses are used to access variables via the host port. HMI

addresses have a 24-bit range on both 24- and 32-bit platforms.

SNMP Object ID (OID)- The Object Identifier is the numeric name assigned to a variable according to the SNMP protocol.

Size - Size is indicated for varying-length data types such as DisplayString and OID. Size is not indicated for fixed types whose size is implied by their data type. Note that for fixed types, the word size may differ depending on the processor type.

Count - Number of entries for array or buffer-type variables. Absence of a Count specification implies a single instance variable, and thus a Count of 1.

Type - Data type of the variable. The options and format of data types are described below in detail.

Attributes - Read-only variables can only be read and can not be modified. Read/Write variables can be read and written. Read/Write - Persistent variables can be read and written. If the persistence feature is enabled, values of these variables will automatically be written to flash for recall at startup.

Default - Value assigned to the variable at startup when persistence is disabled. The values of some Read-only variables reflect system conditions and thus may not have a default value.

Version - Firmware version in which the variable was first introduced. Unless otherwise noted in this field, one can assume variables will be available in the version indicated and all subsequent versions.

6.2 Data Types

6.2.1 DisplayString

A DisplayString is an ASCII string comprised entirely of printable characters.

24-bit HMI: The first word indicates the length of the string in characters. Data is stored three characters per 24-bit word. Character order is MS, Middle, LS. For DisplayString variables, documented Size indicates the largest possible word size of the variable. Size includes the length field. The maximum allowable characters for a DisplayString variable is (Size-1)×3.

32-bit HMI: The first word indicates the length of the string in characters. Data is stored four characters per 32-bit word. Character order is MS, MH, ML, LS. For DisplayString variables, documented Size indicates the largest possible word size of the variable. Size includes the length field. The maximum allowable characters for a DisplayString variable is (Size-1)×4.

6.2.2 OID

An SNMP object identifier is the numeric name of an SNMP variable. OIDs are also used for other purposes including system-unique identifiers.

CobraNet Programmer’s Reference

Management Interface Variable Reference

24-bit HMI: OIDs are presented in their native BER encoding. The first word indicates the length of the encoding in bytes. Data is stored three octets per 24-bit word. Character order is MS, Middle, LS. For OID variables documented Size indicates the largest possible word size for the variable. Size includes the length field. The maximum number of octets for the OID variable encoding is (Size-1)×3.

32-bit HMI: OIDs are presented in their native BER encoding. The first word indicates the length of the encoding in bytes. Data is stored four octets per 32-bit word. Character order is MS, MH, ML, LS. For OID variables documented Size indicates the largest possible word size for the variable. Size includes the length field. The maximum number of octets for the OID variable encoding is (Size-1)×4.

6.2.3 IpAddress

An IpAddress is a 32-bit internet protocol (IP) address.

24-bit HMI: Data is stored in the most-significant 16 bits of 2 consecutive 24-bit words as shown in Ta bl e 10 . The least-significant 8 bits of each location are read as zero and must be written as zero.

Word 1

Table 10. IP address Layout, 24-bit Platforms

MS Middle LS

IP address byte 2 IP address byte 1 0

Word 2

IP address byte 4 IP address byte 3 0

32-bit HMI: Data is stored in a single 32-bit word as illustrated below.

Table 11. IP address Layout, 32-bit Platforms

MS MH ML LS

IP address byte 2 IP address byte 1 IP address byte 4 IP address byte 3

CobraNet Programmer’s Reference

Management Interface Variable Reference

6.2.4 PhysAddress

A 48-bit Ethernet media access control (MAC) address.

24-bit HMI: Data is stored in the most-significant 16 bits of 3 consecutive memory locations as illustrated below. The least-significant 8 bits of each location are read as zero and must be written as zero.

Table 12. MAC address Layout, 24-bit Platforms

MS Middle LS

32-bit HMI: Data is stored in two consecutive words as shown below. A third word is unused and reserved for addressing compatibility with 24-bit platforms.

6.2.5 TimeTicks

TimeTicks is an integer encoding for time durations in units of 100ths of a second.

24-bit HMI: An unsigned timer value is available in two successive 24-bit words. A 32-bit timer value and 15-bit fractional extension are available as shown below. The fractional extension may be used to gain additional accuracy. It may be safely ignored for most applications.

Word 1

Word 2

Word 3

Word 1

Word 2

Word 3

MAC byte 2 MAC byte 1 0

MAC byte 4 MAC byte 3 0

MAC byte 6 MAC byte 5 0

Table 13. MAC address Layout, 32-bit Platforms

MS MH ML LS

MAC byte 2 MAC byte 1 MAC byte 4 MAC byte 3

MAC byte 6 MAC byte 5 unused unused

unused unused unused unused

Table 14. TimeTicks Layout, 24-bit Platforms

MS Middle LS

Word 1

Word 2

Timer MS Timer MH Timer ML

Timer LS Fractional LS Fractional MS

32-bit HMI: TimeTicks value is available as two sucessive 32-bit words. A 32-bit timer value, a 16-bit rollover, and 16-bit fractional extension are availabe as shown below. The fractional extension may be used to gain additional accuracy. The rollover extension may

CobraNet Programmer’s Reference

Management Interface Variable Reference

be used to extend the useful range of the timer. Both may be safely ignored for most applications.

Table 15. TimeTicks Layout, 32-bit Platforms

MS MH ML LS

SNMP: TimeTicks is reported as a 32-bit integer in units of 100ths of a second. For example, a reported value of 1000 indicates a 10-second timer reading. As seen through

SNMP, TimeTicks variables roll over after 2

- over one year).

6.2.6 Counter

Counters are never writable and cannot be reset. They indicate the count value since the interface was last restarted (sysUpTime = 0). Counters roll over to zero after reaching

their maximum value of 2 32-bit platforms.

24-bit HMI: Counter value is represented as a single 24-bit word.

32-bit HMI: Counter value is represented as a single 32-bit word.

6.2.7 Counter2

Counter2 is specific to 24-bit platforms and is a 48-bit unsigned event counter. Counter2

rolls over after 2

identical to the Counter type.

Word 1

Word 2

Rollover MS Rollover LS Timer MS Timer MH

Timer ML Timer LS Fractional LS Fractional MS

100ths of a second (42,949,672.96 seconds

(16,777,216) on 24-bit platforms and 232 (4,294,967,296) on

counts. Counters are never writable. On 32-bit platforms Counter2 is

6.2.8 Integer

24-bit HMI: The counter value is stored in two successive memory locations. The mostsignificant word appears first. It is suggested that one read the MS word followed by LS word followed by a second read of the MS word and verify that the MS word has not changed during the LS read (if so, start over).

32-bit HMI: Counter value is represented in the same single 32-bit word used for the Counter type.

SNMP: Only the least-significant 32-bits of the counter value are reported. The counter

appears to wrap at 2

and conforms to the expected behavior for the standard SNMP

Counter data type.

A single-precision, signed integer. Valid range is -223 (-8,388,608) to 223-1 (8,388,607) on

24-bit platforms and -2

(-2,147,483,648) to 231-1 (2,147,483,647) on 32-bit platforms.

HMI: Signed data is represented in a single word in 2's complement form.

SNMP: On 24-bit platforms, Bad Value error may be reported if the value magnitude

exceeds the 24-bit signed integer range on a set operation.

CobraNet Programmer’s Reference

Management Interface Variable Reference

6.2.9 Integer16

A signed, 16-bit integer. Valid range is -215 (-32,768) to 215-1 (32,767).

24-bit HMI: Signed data is represented in 2's complement form. The most significant 16 bits of the 24-bit host data contain the significant bits. The LS 8 bits are read as zero and must be written as zero.

32-bit HMI: Same as 32-bit Integer type with useful values less than 2

SNMP: Bad Value may be reported if value magnitude exceeds 2

6.2.10 Integer48

Integer48 is specific to 24-bit platforms. This type is a signed, 48-bit integer. On 32-bit

platforms Integer48 is identical to the Integer type.

24-bit HMI: Data is stored in 2 consecutive memory locations. The most significant word

appears first. Signed data is represented in 2's complement form.

32-bit HMI: Signed data is represented as the single word in 2's complement form used for the Integer type.

SNMP: Only the least-significant 32-bits of the value is reported.

(65,536).

on a set operation.

6.3 MIB-II Variables

These variables are common to all SNMP implementations. This common set of management variables is defined in the Internet Engineering Task Force (IETF) standards document RFC 1213.

6.3.1 System

CobraNet Programmer’s Reference

Management Interface Variable Reference

Name

Description

Host Address

SNMP Object ID

sysDescr

Describes type of interface as ASCII text.

Format for 24-bit platforms:

<product specific description> CobraNet version <protocol version>.<major version>.<minor version>[.<manufacturer version>] <hardware platform> rev <hardware rev>

where <hardware platform> is {Referlo, Referhi, CM-1(a), CM-1(m), CS18100, CS18101,

CS18102, CS18110, CS18111, CS18112}

Format for 32-bit platforms:

<product specific description> CobraNet version <protocol version>.<major version>.<minor version>[.<manufacturer version>] <hardware platform><hardware rev>

where <hardware platform> is {Referlo, Referhi, CM-1(a), CM-1(m), CS18100, CS18101, CS18102, CS18110, CS18111, CS18112} and <hardware rev> is the single digit revision number that is part of the Cirrus part number. Example: Cirrus Logic EV-2/CM-2 (CM18101)

CobraNet version 2.10.4 CS181012

Format for RAVE platforms:

<product specific description> CobraNet version <protocol version>.<major version>.<minor version>[.<manufacturer version>]

NOTE: [.<manufacturer version>] is an additional manufacturer-specific string that can be optionally

added to the firmware by Cirrus Logic for 24-bit platforms or added by the OEM using the CNCustom program for 32-bit platforms.

Eaxmple for CS18101: Cirrus Logic EV-2/CM-2 (CM18101) CobraNet version 2.10.5 CS181012

0x100000

1.3.6.1.2.1.1.1

Size

Type

Attributes

Default Value

Implemented Version

84 characters (28 * 3 bytes) for 24-bit platforms. Length was 21 words in 2.9.10. It is now 27 words. 84 characters (21 * 4 bytes) for CS4961xx- and CS1810xx-based platforms.

DisplayString

Read-only

“[manufacturer name] [product name] CobraNet firmware [protocol version].[major version].[minor version].[manufacturer's version (optional, see note above)]”

2.6.3

CobraNet Programmer’s Reference

Management Interface Variable Reference

Name

Description

Host Address

SNMP Object ID

Size

Type

Attributes

Default Value

Implemented Version

Name

Description

sysObjectID

The vendor's authoritative identification of the network management subsystem contained in the entity. This value is allocated within the SMI enterprise sub-tree (1.3.6.1.4.1) and provides an easy and unambiguous means for determining `what kind of box' is being managed. For example, if vendor `Cirrus Logic' was assigned the sub-tree 1.3.6.1.4.1.2680, the identifier `CM-2' could be assigned to 1.3.6.1.4.1.2680.1.2.1.1

0x100100

1.3.6.1.2.1.1.2

60 characters

OID

Read-only

1.3.6.1.4.1.2680.1.2.(CobraNet manufacturer ID).(manufacturer product ID)

2.6.3

sysContact

The identification of the contact person for this managed node, together with information on how to contact this person.

Host Address

SNMP Object ID

Size

Type

Attributes

Default Value

Implemented Version

0x100200

1.3.6.1.2.1.1.4

60 characters

DisplayString

Read/write - Persistent

Zero length string

2.6.3

CobraNet Programmer’s Reference

Management Interface Variable Reference

Name

Description

Host Address

SNMP Object ID

Size

Type

Attributes

Default Value

Implemented Version

Name

Description

Host Address

sysName

A name assigned to this managed node. By convention, this is the node's fully qualified domain name.

0x100300

1.3.6.1.2.1.1.5

60 characters

DisplayString

Read/write - Persistent

Product specific

2.6.3

sysLocation

The physical location of this node (e.g., “telephone closet, 3rd floor”)

0x100400

SNMP Object ID

Size

Type

Attributes

Default Value

Implemented Version

Name

Description

Host Address

SNMP Object ID

Type

Attributes

Default Value

1.3.6.1.2.1.1.6

60 characters

DisplayString

Read/write - Persistent

Zero length string

2.6.3

sysUpTime

Time in 100ths of a second since the network management portion of the system was last reinitialized.

0x100500

1.3.6.1.2.1.1.3

TimeTicks

Read-only

Implemented Version

2.6.3

CobraNet Programmer’s Reference

Management Interface Variable Reference

Name

Description

Host Address

SNMP Object ID

Type

Attributes

Default Value

Implemented Version

sysServices

A value which indicates the set of services supported by this entity. The value is a sum. This sum initially takes the value zero, For each layer, L, in the range 1 through 7, that this node performs transactions for, 2 raised to (L - 1) is added. For example, a node which performs primarily routing functions would have a value of 4 which is equal to (2^(3-1)). A node which is a host offering application services would have a value of 72 or (2^(4-1) + 2^(7-1)). In the context of the Internet suite of protocols, the following service layers are commonly supported: 1 physical (e.g., repeaters), 2 datalink/subnetwork (e.g., bridges), 3 internet (e.g., IP gateways), 4 end-to-end (e.g., IP hosts), 7 applications (e.g., mail relays). For systems including OSI protocols, layers 5 and 6 may also be counted.

0x100502

1.3.6.1.2.1.1.7

Integer

Read-only

2.6.3

6.3.2 Interface

CobraNet Programmer’s Reference

Management Interface Variable Reference

Name

Description

Host Address

SNMP Object ID

Type

Attributes

Default Value

Implemented Version

Name

Description

Host Address

SNMP Object ID

Size

Type

ifNumber

The number of network interfaces (regardless of their current state) present on this system.

0x110000

1.3.6.1.2.1.2.1

Integer

Read-only

2.1.0

ifDescr

A string containing information about the interface. This string should include the name of the manufacturer, the product name and the version of the hardware interface.

0x110001

1.3.6.1.2.1.2.2.1.2

Up to 60 characters.

DisplayString

Attributes

Default Value

Implemented Version

Name

Description

Host Address

SNMP Object ID

Type

Attributes

Default Value

Implemented Version

Read-only

“CobraNet”

2.1.0

ifType

The type of interface, distinguished according to the physical/link protocol(s) immediately `below' the network layer in the protocol stack. Reference RFC 1213 for all type identifiers

0x11000A

1.3.6.1.2.1.2.2.1.3

Integer

Read-only

2.1.0

CobraNet Programmer’s Reference

Management Interface Variable Reference

Name

Description

Host Address

SNMP Object ID

Type

Attributes

Default Value

Implemented Version

Name

Description

Host Address

SNMP Object ID

ifMtu

The size of the largest datagram or ‘packet’ that can be sent/received by the interface, specified in octets. For interfaces that are used for transmitting network datagrams, this is the size of the largest network datagram that can be sent on the interface.

0x11000B

1.3.6.1.2.1.2.2.1.4

Integer

Read-only

1500

2.1.0

ifSpeed

An estimate of the interface's current bandwidth in bits per second or Mbits per second (see Notes below). For interfaces which do not vary in bandwidth or for those where no accurate estimation can be made, this object should contain the nominal bandwidth.

0x11000C

1.3.6.1.2.1.2.2.1.5

Type

Attributes

Default Value

Implemented Version

Notes

Name

Description

Host Address

SNMP Object ID

Type

Attributes

Gauge32

Read-only

100

2.1.0, corrected is 2.6.5 (see Notes below)

Prior to CobraNet firmware version 2.6.5, ifSpeed was incorrectly reported via SNNP in Mbit/second units (100Mbit interface ifSpeed reported as “100”). 2.6.5 correctly reports ifSpeed in bits per second units via SNMP but due to space constraints, ifSpeed is still reported in Mbit per second units via HMI on 24-bit platforms. ifSpeed is reported consistently in bits per second units on 32-bit platforms.

ifPhysAddress

The interface's address at the protocol layer immediately `below' the network layer in the protocol stack.

0x11000D

1.3.6.1.2.1.2.2.1.6

PhysAddress

Read-only

Default Value

Implemented Version

n.a.

2.1.0

CobraNet Programmer’s Reference

Management Interface Variable Reference

Name

Description

Host Address

SNMP Object ID

Type

Attributes

Default Value

Implemented Version

Name

Description

Host Address

ifAdminStatus

The desired state of the interface. The testing(3) state indicates that no operational packets can be passed up(1) -- ready to pass packets down(0)

0x111000

1.3.6.1.2.1.2.2.1.7

Integer

Read/Write

2.1.0

ifOperStatus

The current operational state of the interface. The testing(3) state indicates that no operational packets can be passed. up(1) - ready to pass packets down(0)

0x112000

SNMP Object ID

Type

Attributes

Default Value

Implemented Version

Name

Description

Host Address

SNMP Object ID

Type

Attributes

Default Value

1.3.6.1.2.1.2.2.1.8

Integer

Read-only

2.1.0

ifLastChange

The value of sysUpTime at the time the interface entered its current operational state. If the current state was entered prior to the last re- initialization of the local network management subsystem, then this object contains a zero value.

0x112001

1.3.6.1.2.1.2.2.1.9

TimeTicks

Read-only

n.a.

Implemented Version

2.1.0

CobraNet Programmer’s Reference

Management Interface Variable Reference

Name

Description

Host Address

SNMP Object ID

Type

Attributes

Default Value

Implemented Version

Name

Description

Host Address

SNMP Object ID

Type

ifInOctets

The total number of octets received on the interface, including framing characters.

0x112016

1.3.6.1.2.1.2.2.1.10

Counter48

Read-only

2.1.0

ifInUcastPkts

The number of subnetwork-unicast packets delivered to a higher-layer protocol.

0x112018

1.3.6.1.2.1.2.2.1.11

Counter

Attributes

Default Value

Implemented Version

Name

Description

Host Address

SNMP Object ID

Type

Attributes

Default Value

Implemented Version

Read-only

2.1.0

ifInNUcastPkts

The number of non-unicast (i.e., subnetwork- broadcast or subnetwork-multicast) packets delivered to a higher-layer protocol.

0x112019

1.3.6.1.2.1.2.2.1.12

Counter

Read-only

2.1.0

CobraNet Programmer’s Reference

Management Interface Variable Reference

Name

Description

Host Address

SNMP Object ID

Type

Attributes

Default Value

Implemented Version

Name

Description

Host Address

SNMP Object ID

ifInDiscards

The number of inbound packets which were chosen to be discarded even though no errors had been detected to prevent their delivery to a higher-layer protocol. One possible reason for discarding such a packet could be lack of buffer space.

0x11201A

1.3.6.1.2.1.2.2.1.13

Counter

Read-only

2.1.0

ifInErrors

The number of inbound packets that contained errors preventing delivery to a higher-layer protocol.

0x11201B

1.3.6.1.2.1.2.2.1.14

Type

Attributes

Default Value

Implemented Version

Name

Description

Host Address

SNMP Object ID

Type

Attributes

Default Value

Implemented Version

Counter

Read-only

2.1.0

ifInUnknownProtos

The number of packets received which were discarded due to an unknown or unsupported protocol.

0x11201C

1.3.6.1.2.1.2.2.1.15

Counter

Read-only

2.1.0

CobraNet Programmer’s Reference

Management Interface Variable Reference

Name

Description

Host Address

SNMP Object ID

Type

Attributes

Default Value

Implemented Version

Name

Description

Host Address

SNMP Object ID

Type

ifOutOctets

The total number of octets transmitted by the interface, including framing characters.

0x11201D - 0x11201E

1.3.6.1.2.1.2.2.1.16

Counter48

Read-only

2.1.0

ifOutUcastPkts

The total number of packets that higher-level protocols requested be transmitted to a subnetworkunicast address, including those that were discarded or not sent.

0x11201F

1.3.6.1.2.1.2.2.1.17

Counter

Attributes

Default Value

Implemented Version

Name

Description

Host Address

SNMP Object ID

Type

Attributes

Default Value

Implemented Version

Read-only

2.1.0

ifOutNUcastPkts

The total number of packets that higher-level protocols requested be transmitted to a non- unicast (i.e., a subnetwork-broadcast or subnetwork-multicast) address, including those that were discarded or not sent.

0x112020

1.3.6.1.2.1.2.2.1.18

Counter

Read-only

2.1.0

CobraNet Programmer’s Reference

Management Interface Variable Reference

Name

Description

Host Address

SNMP Object ID

Type

Attributes

Default Value

Implemented Version

Name

Description

Host Address

SNMP Object ID

ifOutDiscards

The number of outbound packets which were chosen to be discarded even though no errors had been detected to prevent their transmission. One possible reason for discarding such a packet could be to free up buffer space.

0x112021

1.3.6.1.2.1.2.2.1.19

Counter

Read-only

2.1.0

ifOutErrors

The number of outbound packets that could not be transmitted due to errors.

0x112022

1.3.6.1.2.1.2.2.1.20

Type

Attributes

Default Value

Implemented Version

Name

Description

Host Address

SNMP Object ID

Type

Attributes

Default Value

Implemented Version

Counter

Read-only

2.1.0

ifOutQLen

The length of the output packet queue (in packets)

0x112023

1.3.6.1.2.1.2.2.1.21

Integer

Read-only

n.a.

2.6.1

CobraNet Programmer’s Reference

Management Interface Variable Reference

Name

Description

Host Address

SNMP Object ID

Size

Type

Attributes

Default Value

Implemented Version

ifSpecific

A reference to MIB definitions specific to the particular media being used to implement the interface. For example, if the interface is implemented by Ethernet, then the value of this object refers to a document defining objects specific to Ethernet. If this information is not present, its value should be set to the OBJECT IDENTIFIER { 0 0 }, which is a syntactically valid object identifier, and any conformant implementation of ASN.1 and BER must be able to generate and recognize this value.

0x112024

1.3.6.1.2.1.2.2.1.22

OID

Read-only

0.0

2.6.1

6.3.3 Address Translation

The Address Translations are deprecated. These variables are no longer available via SNMP.

CobraNet Programmer’s Reference

Management Interface Variable Reference

Name

Description

Host Address

SNMP Object ID

Type

Attributes

Default Value

Implemented Version

Name

Description

Host Address

SNMP Object ID

Type

atIfIndex

The interface on which this entry's equivalence is effective. The interface identified by a particular value of this index is the same interface as identified by the same value of ifIndex.

0x120000

Not available via SNMP

Integer

Read-only

2.1.0

atPhysAddress

MAC address of the device. Use of ifPhysAddress is preferred for determining the MAC address.

0x120001

Not available via SNMP

PhysAddress

Attributes

Default Value

Implemented Version

Name

Description

Host Address

SNMP Object ID

Type

Attributes

Default Value

Implemented Version

Read-only

As assigned by manufacturer

2.1.0

atNetAddress

IP address of the device. Obtaining the IP address via SNMP should not be a necessary operation you need to know the IP address in order to send the query. Via HMI, the IP address may be monitored and manipulated via the IP Monitor variables.

0x120004

Not available via SNMP

IpAddress

Read-only

As assigned by RARP, BOOTP or IP monitor variables.

2.1.0

CobraNet Programmer’s Reference

Management Interface Variable Reference

6.3.4 IP

Name

Description

Host Address

SNMP Object ID

Type

Attributes

Default Value

Implemented Version

Name

Description

Host Address

SNMP Object ID

ipForwarding

The indication of whether this entity is acting as an IP gateway to forward of datagrams received by, but not addressed to, this entity. IP gateways forward datagrams. IP hosts do not (except those source-routed via the host).

0x130000

1.3.6.1.2.1.4.1

Integer

Read/Write

Always reads 2

2.6.0

ipDefaultTTL

The default value inserted into the Time-To-Live field of the IP header of datagrams originated at this entity when a TTL value is not supplied by the transport layer protocol.

0x130001

1.3.6.1.2.1.4.2

Type

Attributes

Default Value

Implemented Version

Name

Description

Host Address

SNMP Object ID

Type

Attributes

Default Value

Implemented Version

Integer

Read/Write

128

2.6.0

ipInReceives

The total number of input datagrams received, including those received in error.

0x131000

1.3.6.1.2.1.4.3

Counter

Read-only

2.6.0

CobraNet Programmer’s Reference

Management Interface Variable Reference

Name

Description

Host Address

SNMP Object ID

Type

Attributes

Default Value

Implemented Version

Name

Description

Host Address

ipInHdrErrors

The number of input datagrams discarded due to errors in their IP headers, including bad checksums, version number mismatch, other format errors, time-to-live exceeded, errors discovered in processing their IP options, etc.

0x131001

1.3.6.1.2.1.4.4

Counter

Read-only

2.6.0

ipInAddrErrors

The number of input datagrams discarded because the IP address in the IP header's destination field was not a valid address to be received at this entity. This count includes invalid addresses (e.g.,

0.0.0.0) and addresses of unsupported Classes (e.g., Class E). For entities which are not IP Gateways and therefore do not forward datagrams, this counter includes datagrams discarded because the destination address was not a local address.

0x131002

SNMP Object ID

Type

Attributes

Default Value

Implemented Version

Name

Description

Host Address

SNMP Object ID

Type

Attributes

Default Value

1.3.6.1.2.1.4.5

Counter

Read-only

2.6.0

ipForwDatagrams

The number of input datagrams for which this entity was not the final IP destination, as a result of which an attempt was made to find a route to forward them to the final destination. In entities which do not act as IP Gateways, this counter will include only those packets which were Source-Routed via this entity, and the Source- Route option processing was successful.

Not available

1.3.6.1.2.1.4.6

Counter

Read-only

Implemented Version

2.6.0

CobraNet Programmer’s Reference

Management Interface Variable Reference

Name

Description

Host Address

SNMP Object ID

Type

Attributes

Default Value

Implemented Version

Name

Description

Host Address

SNMP Object ID

Type

ipInUnknownProtos

The number of locally-addressed datagrams received successfully but discarded because of an unknown or unsupported protocol.

0x131003

1.3.6.1.2.1.4.7

Counter

Read-only

2.6.0

ipInDiscards

The number of IP datagrams received successfully but which were discarded (e.g., for lack of buffer space). Note that this counter does not include datagrams discarded while awaiting re-assembly.

0x131004

1.3.6.1.2.1.4.8

Counter

Attributes

Default Value

Implemented Version

Name

Description

Host Address

SNMP Object ID

Type

Attributes

Default Value

Implemented Version

Read-only

2.6.0

ipInDelivers

The total number of input datagrams successfully delivered to IP user-protocols (including ICMP)

0x131005

1.3.6.1.2.1.4.9

Counter

Read-only

2.6.0

CobraNet Programmer’s Reference

Management Interface Variable Reference

Name

Description

Host Address

SNMP Object ID

Type

Attributes

Default Value

Implemented Version

Name

Description

Host Address

SNMP Object ID

ipOutRequests

The total number of IP datagrams which local IP user-protocols (including ICMP) supplied to IP in requests for transmission. Note that this does not include datagrams counted in ipForwDatagrams.

0x131006

1.3.6.1.2.1.4.10

Counter

Read-only

2.6.0

ipOutDiscards

The number of IP datagrams for which no problem existed to prevent their transmission, but which were discarded (e.g., for lack of buffer space). Note that this counter would include datagrams counted in ipForwDatagrams if any such packets met this (discretionary) discard criterion.

Not available

1.3.6.1.2.1.4.11

Type

Attributes

Default Value

Implemented Version

Name

Description

Host Address

SNMP Object ID

Type

Attributes

Default Value

Implemented Version

Counter

Read-only

2.6.0

ipOutNoRoutes

The number of IP datagrams discarded because no route could be found to transmit them to their destination. Note that this counter includes packets counted in ipForwDatagrams which meet this `no-route' criterion. This includes any datagrams which cannot route because all of its default gateways are down.

Not available

1.3.6.1.2.1.4.12

Counter

Read-only

2.6.0

CobraNet Programmer’s Reference

Management Interface Variable Reference

Name

Description

Host Address

SNMP Object ID

Type

Attributes

Default Value

Implemented Version

Name

Description

Host Address

SNMP Object ID

Type

ipReasmTimeout

The maximum number of seconds which received fragments are held while they are awaiting reassembly.

Not available

1.3.6.1.2.1.4.13

Integer

Read-only

2.6.0

ipReasmReqds

The number of IP fragments received which needed to be reassembled.

0x131007

1.3.6.1.2.1.4.14

Counter

Attributes

Default Value

Implemented Version

Name

Description

Host Address

SNMP Object ID

Type

Attributes

Default Value

Implemented Version

Read-only

2.6.0

ipReasmOKs

The number of IP datagrams successfully re-assembled.

Not available

1.3.6.1.2.1.4.15

Counter

Read-only

2.6.0

CobraNet Programmer’s Reference

Management Interface Variable Reference

Name

Description

Host Address

SNMP Object ID

Type

Attributes

Default Value

Implemented Version

Name

Description

Host Address

ipReasmFails

The number of failures detected by the IP re- assembly algorithm (for whatever reason: timed out, errors, etc). Note that this is not necessarily a count of discarded IP fragments since some algorithms (notably the algorithm in RFC 815) can lose track of the number of fragments by combining them as they are received. This value will always increment on receipt of a fragmented packet as CobraNet does not support packet re-assembly

0x131007 (same as ipReasmReqds)

1.3.6.1.2.1.4.16

Counter

Read-only

2.6.0

ipFragOKs

The number of IP datagrams that have been successfully fragmented at this entity. The CobraNet interface does not support fragmentation. This variable will always read 0.

Not available

SNMP Object ID

Type

Attributes

Default Value

Implemented Version

Name

Description

Host Address

SNMP Object ID

Type

Attributes

Default Value

1.3.6.1.2.1.4.17

Counter

Read-only

2.6.0

ipFragFails

The number of IP datagrams that have been discarded because they needed to be fragmented at this entity but could not be, e.g., because their Don't Fragment flag was set. The CobraNet interface does not support fragmentation. This variable will always read 0.

Not available

1.3.6.1.2.1.4.18

Counter

Read-only

Implemented Version

2.6.0

CobraNet Programmer’s Reference

Management Interface Variable Reference

Name

Description

Host Address

SNMP Object ID

Type

Attributes

Default Value

Implemented Version

Name

Description

Host Address

SNMP Object ID

ipFragCreates

The number of IP datagram fragments that have been generated as a result of fragmentation at this entity. The CobraNet interface does not support fragmentation. This variable will always read 0.

Not available

1.3.6.1.2.1.4.19

Counter

Read-only

2.6.0

ipRoutingDiscards

The number of routing entries which were chosen to be discarded even though they are valid. One possible reason for discarding such an entry could be to free-up buffer space for other routing entries. The CobraNet interface does not support routing. This variable will always read 0.

Not available

1.3.6.1.2.1.4.23

Type

Attributes

Default Value

Implemented Version

Counter

Read-only

2.6.0

6.3.5 UDP

CobraNet Programmer’s Reference

Management Interface Variable Reference

Name

Description

Host Address

SNMP Object ID

Type

Attributes

Default Value

Implemented Version

Name

Description

Host Address

SNMP Object ID

Type

udpInDatagrams

The total number of UDP datagrams delivered to UDP users.

0x140000

1.3.6.1.2.1.7.1

Counter

Read-only

2.6.0

udpNoPorts

The total number of received UDP datagrams for which there was no application at the destination port.

0x140001

1.3.6.1.2.1.7.2

Counter

Attributes

Default Value

Implemented Version

Name

Description

Host Address

SNMP Object ID

Type

Attributes

Default Value

Implemented Version

Read-only

2.6.0

udpInErrors

The number of received UDP datagrams that could not be delivered for reasons other than lack of an application at the destination port.

0x140002

1.3.6.1.2.1.7.3

Counter

Read-only

2.6.0

CobraNet Programmer’s Reference

Management Interface Variable Reference

Name

Description

Host Address

SNMP Object ID

Type

Attributes

Default Value

Implemented Version

Name

Description

Host Address

SNMP Object ID

Type

udpOutDatagrams

The total number of UDP datagrams sent from this entity.

0x140003

1.3.6.1.2.1.7.4

Counter

Read-only

2.6.0

udpLocalAddress

The local IP address for this UDP listener. In the case of a UDP listener which is willing to accept datagrams for any IP interface associated with the node, the value 0.0.0.0 is used.

N.A.

IpAddress

Attributes

Default Value

Implemented Version

Name

Description

Host Address

SNMP Object ID

Type

Attributes

Default Value

Implemented Version

Read-only

N.A.

Not supported

udpLocalPort

The local port number for this UDP listener.

N.A.

Integer16

Read-only

N.A.

Not supported

6.3.6 SNMP

CobraNet Programmer’s Reference

Management Interface Variable Reference

Name

Description

Host Address

SNMP Object ID

Type

Attributes

Default Value

Implemented Version

Name

Description

Host Address

SNMP Object ID

Type

snmpInPkts

The total number of SNMP Messages received from the transport service

0x150000

1.3.6.1.2.1.11.1

Counter

Read-only

2.6.0

snmpOutPkts

The total number of SNMP Messages passed to the transport service.

0x150001

1.3.6.1.2.1.11.2

Counter

Attributes

Default Value

Implemented Version

Name

Description

Host Address

SNMP Object ID

Type

Attributes

Default Value

Implemented Version

Read-only

2.6.0

snmpInBadVersions

The total number of SNMP Messages received which were for an unsupported SNMP version.

0x150002

1.3.6.1.2.1.11.3

Counter

Read-only

2.6.0

CobraNet Programmer’s Reference

Management Interface Variable Reference

Name

Description

Host Address

SNMP Object ID

Type

Attributes

Default Value

Implemented Version

Name

Description

Host Address

SNMP Object ID

Type

snmpInBadCommunityNames

The total number of SNMP Messages received which used an unknown community name.

0x150003

1.3.6.1.2.1.11.4

Counter

Read-only

2.6.0

snmpInBadCommunityUses

The total number of SNMP Messages received for which an operation was not allowed by the SNMP community named in the Message.

0x150004

1.3.6.1.2.1.11.5

Counter

Attributes

Default Value

Implemented Version

Name

Description

Host Address

SNMP Object ID

Type

Attributes

Default Value

Implemented Version

Read-only

2.6.0

snmpInASNParseErrs

The total number of ASN.1 or BER errors encountered when decoding received SNMP Messages.

0x150005

1.3.6.1.2.1.11.6

Counter

Read-only

2.6.0

CobraNet Programmer’s Reference

Management Interface Variable Reference

Name

Description

Host Address

SNMP Object ID

Type

Attributes

Default Value

Implemented Version

Name

Description

Host Address

SNMP Object ID

Type

snmpInTooBigs

The total number of SNMP PDUs received for which the value of the error-status field was `tooBig'.

Not available

1.3.6.1.2.1.11.8

Counter

Read-only

Always reads 0

2.6.0

snmpInNoSuchNames

The total number of SNMP PDUs received for which the value of the error-status field was `noSuchName'.

Not available

1.3.6.1.2.1.11.9

Counter

Attributes

Default Value

Implemented Version

Name

Description

Host Address

SNMP Object ID

Type

Attributes

Default Value

Implemented Version

Read-only

Always reads 0

2.6.0

snmpInBadValues

The total number of SNMP PDUs received for which the value of the error-status field was `badValue'.

Not available

1.3.6.1.2.1.11.10

Counter

Read-only

Always reads 0

2.6.0

CobraNet Programmer’s Reference

Management Interface Variable Reference

Name

Description

Host Address

SNMP Object ID

Type

Attributes

Default Value

Implemented Version

Name

Description

Host Address

SNMP Object ID

snmpInReadOnlys

The total number of valid SNMP PDUs received for which the value of the error-status field was `readOnly'. Note that it is a protocol error to generate an SNMP PDU which contains the value `readOnly' in the error-status field. This object is provided as a means of detecting incorrect implementations of SNMP.

Not available

1.3.6.1.2.1.11.11

Counter

Read-only

Always reads 0

2.6.0

snmpInGenErrs

The total number of SNMP PDUs received for which the value of the error-status field was `genErr'.

Not Available

1.3.6.1.2.1.11.12

Type

Attributes

Default Value

Implemented Version

Name

Description

Host Address

SNMP Object ID

Type

Attributes

Default Value

Implemented Version

Counter

Read-only

Always reads 0

2.6.0

snmpInTotalReqVars

The total number of MIB objects which have been retrieved successfully as a result of receiving valid SNMP Get-Request and Get-Next PDUs.

0x150006

1.3.6.1.2.1.11.13

Counter

Read-only

2.6.0

CobraNet Programmer’s Reference

Management Interface Variable Reference

Name

Description

Host Address

SNMP Object ID

Type

Attributes

Default Value

Implemented Version

Name

Description

Host Address

SNMP Object ID

Type

snmpInTotalSetVars

The total number of MIB objects which have been altered successfully as a result of receiving valid SNMP Set-Request PDUs.

0x150007

1.3.6.1.2.1.11.14

Counter

Read-only

2.6.0

snmpInGetRequests

The total number of SNMP Get-Request PDUs which have been accepted and processed.

0x150008

1.3.6.1.2.1.11.15

Counter

Attributes

Default Value

Implemented Version

Name

Description

Host Address

SNMP Object ID

Type

Attributes

Default Value

Implemented Version

Read-only

2.6.0

snmpInGetNexts

The total number of SNMP Get-Next PDUs which have been accepted and processed.

0x150009

1.3.6.1.2.1.11.16

Counter

Read-only

2.6.3

CobraNet Programmer’s Reference

Management Interface Variable Reference

Name

Description

Host Address

SNMP Object ID

Type

Attributes

Default Value

Implemented Version

Name

Description

Host Address

SNMP Object ID

Type

snmpInSetRequests

The total number of SNMP Set-Request PDUs which have been accepted and processed.

0x15000A

1.3.6.1.2.1.11.17

Counter

Read-only

2.6.3

snmpInGetResponses

The total number of SNMP Get-Response PDUs which have been accepted and processed.

Not available

1.3.6.1.2.1.11.18

Counter

Attributes

Default Value

Implemented Version

Name

Description

Host Address

SNMP Object ID

Type

Attributes

Default Value

Implemented Version

Read-only

Always reads 0

2.6.3

snmpInTraps

The total number of SNMP Trap PDUs which have been accepted and processed.

Not available

1.3.6.1.2.1.11.19

Counter

Read-only

Always reads 0

2.6.3

CobraNet Programmer’s Reference

Management Interface Variable Reference

Name

Description

Host Address

SNMP Object ID

Type

Attributes

Default Value

Implemented Version

Name

Description

Host Address

SNMP Object ID

Type

snmpOutTooBigs

The total number of SNMP PDUs generated for which the value of the error-status field was `tooBig.'

0x15000B

1.3.6.1.2.1.11.20

Counter

Read-only

2.6.3

snmpOutNoSuchNames

The total number of SNMP PDUs generated for which the value of the error-status was `noSuchName'.

0x15000C

1.3.6.1.2.1.11.21

Counter

Attributes

Default Value

Implemented Version

Name

Description

Host Address

SNMP Object ID

Type

Attributes

Default Value

Implemented Version

Read-only

2.6.3

snmpOutBadValues

The total number of SNMP PDUs generated for which the value of the error-status field was `badValue'.

0x15000D

1.3.6.1.2.1.11.22

Counter

Read-only

2.6.3

CobraNet Programmer’s Reference

Management Interface Variable Reference

Name

Description

Host Address

SNMP Object ID

Type

Attributes

Default Value

Implemented Version

Name

Description

Host Address

SNMP Object ID

Type

snmpOutGenErrs

The total number of SNMP PDUs generated for which the value of the error-status field was `genErr'.

0x15000E

1.3.6.1.2.1.11.24

Counter

Read-only

2.6.3

snmpOutGetRequests

The total number of SNMP Get-Request PDUs generated.

Not available

1.3.6.1.2.1.11.25

Counter

Attributes

Default Value

Implemented Version

Name

Description

Host Address

SNMP Object ID

Type

Attributes

Default Value

Implemented Version

Read-only

Always reads 0

2.6.3

snmpOutGetNexts

The total number of SNMP Get-Next PDUs generated.

Not available

1.3.6.1.2.1.11.26

Counter

Read-only

Always reads 0

2.6.3

CobraNet Programmer’s Reference

Management Interface Variable Reference

Name

Description

Host Address

SNMP Object ID

Type

Attributes

Default Value

Implemented Version

Name

Description

Host Address

SNMP Object ID

Type

snmpOutSetRequests

The total number of SNMP Set-Request PDUs generated.

Not available

1.3.6.1.2.1.11.27

Counter

Read-only

Always reads 0

2.6.3

snmpOutGetResponses

The total number of SNMP Get-Response PDUs generated.

0x150001 (same as snmpOutPackets)

1.3.6.1.2.1.11.28

Counter

Attributes

Default Value

Implemented Version

Name

Description

Host Address

SNMP Object ID

Type

Attributes

Default Value

Implemented Version

Read-only

2.6.3

snmpOutTraps

The total number of SNMP Trap PDUs generated.

Not available

1.3.6.1.2.1.11.29

Counter

Read-only

Always reads 0

2.6.3

CobraNet Programmer’s Reference

Management Interface Variable Reference

Name

Description

Host Address

SNMP Object ID

Type

Attributes

Default Value

Implemented Version

Name

Description

Host Address

snmpEnableAuthenTraps

Indicates whether the SNMP agent process is permitted to generate authentication-failure traps. The value of this object overrides any configuration information. It provides a means to disable all authentication-failure traps.

0x15000F

1.3.6.1.2.1.11.30

Integer

Read-only

Always reads 2

2.6.0

snmpSilentDrops

The total number of GetRequest-PDUs, GetNextRequest-PDUs, GetBulkRequest-PDUs, SetRequest-PDUs, and InformRequest-PDUs received which were silently dropped because the size of a reply containing an alternate Response-PDU with an empty variable-bindings field was greater than either a local constraint or the maximum message size associated with the originator of the request.

Not available

SNMP Object ID

Type

Attributes

Default Value

Implemented Version

Name

Description

Host Address

SNMP Object ID

Type

Attributes

Default Value

1.3.6.1.2.1.11.31

Counter

Read-only

Always reads 0

2.6.3

snmpProxyDrops

The total number of GetRequest-PDUs, GetNextRequest-PDUs, GetBulkRequest-PDUs, SetRequest-PDUs, and InformRequest-PDUs received which were silently dropped because the transmission of the (possibly translated) message to a proxy target failed in a manner (other than a time-out) such that no Response-PDU could be returned.

Not available

1.3.6.1.2.1.11.32

Counter

Read-only

Always reads 0

Implemented Version

2.6.3

6.4 CobraNet Variables

6.4.1 Firmware

CobraNet Programmer’s Reference

Management Interface Variable Reference

Name

Description

Host Address

SNMP Object ID

Type

Attributes

Implemented Version

Name

Description

Host Address

SNMP Object ID

Type

Attributes

firmwareProtocolVersion

Highest CobraNet protocol version supported by firmware. Current protocol version is 2. A protocol version of 0 indicates an unsupported test version of firmware.

0x0

1.3.6.1.4.1.2680.1.1.1.1

Integer

Read-only

2.1.0

firmwareMajorVersion

CobraNet firmware major revision number.

0x1

1.3.6.1.4.1.2680.1.1.1.2

Integer

Read-only

Implemented Version

Name

Description

Host Address

SNMP Object ID

Type

Attributes

Implemented Version

2.1.0

firmwareMinorVersion

CobraNet firmware minor revision number.

0x2

1.3.6.1.4.1.2680.1.1.1.3

Integer

Read-only

2.1.0

CobraNet Programmer’s Reference

Management Interface Variable Reference

Name

Description

Host Address

SNMP Object ID

Type

Attributes

Implemented Version

Name

Description

Host Address

SNMP Object ID

Type

Attributes

firmwareBootVersion

Configuration record revision number. The configuration record contains the MAC address for the interface and other permanent initialization parameters.

0x3

1.3.6.1.4.1.2680.1.1.1.4

Integer

Read-only

2.1.0

firmwareMfgId

Identifies the manufacturer of the CobraNet device. 0 represents unknown.

0x4

1.3.6.1.4.1.2680.1.1.1.5

Integer

Read-only

Implemented Version

Name

Description

Host Address

SNMP Object ID

Type

Attributes

Implemented Version

2.1.0

firmwareMfgProductId

Identifies product type per manufacturer. Product identifiers are unique per manufacturer identifier. 0 represents unknown product.

0x5

1.3.6.1.4.1.2680.1.1.1.6

Integer

Read-only

2.1.0

CobraNet Programmer’s Reference

Management Interface Variable Reference

Name

Description

Host Address

SNMP Object ID

Type

Attributes

Implemented Version

Name

Description

firmwareMfgVersion

A manufacturer assigned minor revision number for firmware. A non-zero value indicates manufacturer has made some modification to the standard firmware as released by Cirrus Logic.

0x6

1.3.6.1.4.1.2680.1.1.1.7

Integer

Read-only

2.1.0

firmwareRestart

Reboots the interface when set to a non-zero value. Invoking this function will cause loss of communications. The interface will attempt to send a response to an SNMP set request before restarting. Due to the nature of SNMP, receipt of such a response by the manager is not guaranteed. Invoking this feature via HMI will cause the HMI to become inoperable until the interface has completed re-initialization. A successful restart can be verified by reading the sysUpTime variable. sysUpTime returns to 0 following a restart. A restart via SNMP may adversely affect an HMI connected host processor. Care should be taken to insure that a host processor attempting to communicate via HMI during reset can recover from the HMI’s failure to respond and, further, that the host processor will continue to function properly following reinitialization of the MI variables to their default or persistent values.

Host Address

SNMP Object ID

Type

Attributes

Default Value

Implemented Version

Name

Description

Host Address

SNMP Object ID

Type

Attributes

Implemented Version

0x100

1.3.6.1.4.1.2680.1.1.1.8

Integer

Read/Write

2.6.3. Not implemented on 32-bit platforms.

firmwareFreeCycles

Free CPU cycles in thousandths. For example, 475 means 47.5% of CPU cycles are free, i.e., running idle loop.

0x9

1.3.6.1.4.1.2680.1.1.1.11

Integer32 for CS18101-based firmware. Integer24 for Motorola-based firmware.

Read-only

2.9.12 for Motorola-based firmware; 2.10.5 for CS1810xx-based firmware.

CobraNet Programmer’s Reference

Management Interface Variable Reference

6.4.2 Hardware Identification

Different platforms and hardware version have different channel and processing capacities. By recognizing the capabilities of the interface, the host may optimize the configuration to take advantage of the capabilities.

Before the introduction of the variables documented below, the host could use sysDescr, sysObjectID and firmwareVersion* to determine the capabilities. With the introduction of the CM-1 rev F, these variables no longer fully characterize the interface. CM-1 rev F features a memory speed increase and thus a capacity improvement over CM-1 rev E and previous revisions.

Name

Description

Host Address

SNMP Object ID

Type

Attributes

Implemented Version

Name

firmwareHardwarePlatfor m

CobraNet interface hardware platform. 1 - RAVE 2 - Reference design 3 - High capacity reference design 4 - CM-1 with AMD flash memory (alternate supplier) 5 - CM-1 with Micron flash memory (standard supplier) 18100 - CS18100 18101 - CS18101 18102 - CS18102 18110 - CS18110 18111 - CS18111 18112 - CS18112

0x7

1.3.6.1.4.1.2680.1.1.1.9

Integer

Read-only

2.9.10, 2.10.5

firmwareHardwareVersion

Version number specific to platform.

Description

Host Address

SNMP Object ID

Type

Attributes

Implemented Version

1 - Reported for all RAVE and reference design hardware as these platforms lack hardware version

identification feature: CM-1 rev A-C (95Mhz) and CS18101 rev 1 (prototypes). 2 - CM-1 rev C-E (100 MHz-capable), CS18xxx rev 2. 3 - CM-1 rev F (1 WS-capable)

0x8

1.3.6.1.4.1.2680.1.1.1.10

Integer

Read-only

2.9.10 (2.10.5 for CS18101-based firmware)

6.4.3 Flash

CobraNet Programmer’s Reference

Management Interface Variable Reference

Name

Description

Host Address

SNMP Object ID

Type

Attributes

Implemented Version

Name

Description

Host Address

SNMP Object ID

Type

flashTotalSize

Total flash memory size in bytes.

0x1000

1.3.6.1.4.1.2680.1.1.2.1

Integer

Read-only

2.1.0

flashSectorSize

Largest flash sector size in bytes. Sector size is visible via TFTP where each sector is presented as a system file. Some flash memories have sectors that vary in size and it is not safe to use this variable to determine sector size. The safe way to determine sector size is to read each sector via TFTP. The amount of data returned will indicate the sector size.

0x1001

1.3.6.1.4.1.2680.1.1.2.2

Integer

Attributes

Implemented Version

Name

Description

Host Address

SNMP Object ID

Type

Attributes

Implemented Version

Read-only

2.1.0

flashPersistSequence

Sequence number for persistence storage. This gives an approximate indication of the wear on the flash memory from persistent stores. The sequence number is incremented each time a sector is erased to make room for a persistent store. Typically two sectors are used for persistent storage. The sequence number divided by the number of sectors used for persistence yields the approximate erase cycle count each sector has experienced. Flash memory is typically rated for no less than 100,000 erase cycles.

0x1002

1.3.6.1.4.1.2680.1.1.2.3

Counter

Read-only

2.8.1

CobraNet Programmer’s Reference

Management Interface Variable Reference

Name

Description

Host Address

SNMP Object ID

Type

Attributes

Implemented Version

Name

Description

Host Address

SNMP Object ID

Type

Attributes

flashPersistType

Indicates the type identifier for the persistent store dataset. If firmware is updated to a version that uses a different dataset type (or different size), persistent settings will be lost.

0x1003

1.3.6.1.4.1.2680.1.1.2.4

Integer

Read-only

2.8.1

flashPersistSize

Size in words of the persistent store dataset. If firmware is updated to a version that uses a different dataset size (or different type), persistent settings will be lost.

0x1004

1.3.6.1.4.1.2680.1.1.2.5

Integer

Read-only

Implemented Version

Name

Description

Host Address

SNMP Object ID

Type

Attributes

Default Value

Implemented Version

2.8.1

flashPersistStores

The number of times variables have been written to flash during sysUpTime. Use of flashPersistAck is preferred to determine completion of a persistent save operation.

0x1005

1.3.6.1.4.1.2680.1.1.2.6

Counter

Read-only

2.8.1

CobraNet Programmer’s Reference

Management Interface Variable Reference

Name

Description

Host Address

SNMP Object Identifier

Type

Attributes

Implemented Version

Name

Description

Host Address

SNMP Object ID

Type

Attributes

flashTAcknowledge

A semaphore variable updated to the value of flashTRequest on completion of a flash write.

0x1006

Not available via SNMP

Integer

Read-only

2.8.6

flashPersistEnable

Non-zero value enables variable persistence feature. Read/write - Persistent type variables will be automatically written to non-volatile memory when changed. Values will be restored on power-up.

0x1100

1.3.6.1.4.1.2680.1.1.2.7

Integer

Read/write - Persistent

Default Value

Implemented Version

Name

Description

Host Address

SNMP Object ID

Type

Attributes

Default Value

Implemented Version

2.8.1

flashPersistAck

Forces a write of variables to non-volatile memory when set to a non-zero value. Value returns to zero when write has completed. This value will not change if persistence is disabled. This feature is recommended for use during factory configuration where writing and confirmation of success must be done in a timely manner. In normal use it is best to let the interface schedule writes to nonvolatile memory. Over-use of this feature can result in excessive wear on the flash device.

0x1200

1.3.6.1.4.1.2680.1.1.2.8

Integer

Read/Write

2.8.1

CobraNet Programmer’s Reference

Management Interface Variable Reference

Name

Description

Host Address

SNMP Object Identifier

Type

Attributes

Implemented Version

Name

Description

Host Address

SNMP Object Identifier

Type

flashTRequest

When changed, causes data transfer to begin between flash memory and bridgeTxPktBuffer. Transfer begins when set to a value different than flashTAcknowledge.

0x1201

Not available via SNMP

Integer

Read/Write

2.8.6

flashTAddress

Specifies the source (read) or destination (write) address in flash memory. This address is a byte offset into flash memory. For an erase operations this variable can be set to any address within the sector to be erased. Following read and write operations flashTAddress is incremented by flashTLength (flashTAddress += flashTLength)

0x1202

Not available via SNMP

Integer

Attributes

Implemented Version

Name

Description

Host Address

SNMP Object Identifier

Type

Attributes

Implemented Version

Read/Write

2.8.6

flashTLength

Specifies the number of bytes to be transferred between flash and transmit buffer. This value should never exceed the byte size of bridgeTxPktBuffer. A flash operation is not allowed to straddle a sector boundary. This variable is ignored for erase operations.

0x1203

Not available via SNMP

Integer

Read/Write

2.8.6

CobraNet Programmer’s Reference

Management Interface Variable Reference

Name

Description

Host Address

SNMP Object Identifier

Type

Attributes

Implemented Version

flashTDirection

Specifies whether the transaction is a flash sector read, write or erase. 0 - Read flash to transmit buffer 1 - Write flash from transmit buffer 2 - Erase flash sector

0x1204

Not available via SNMP

Integer

Read/Write

2.8.6

CobraNet Programmer’s Reference

Management Interface Variable Reference

6.4.4 Errors

Name

Description

Host Address

SNMP Object ID

Type

Attributes

Default Value

Implemented Version

Name

Description

errorPOSTResults

Power on self-test results. 0 - no errors detected. Currently the CobraNet interface does not recover from a POST failure. This variable will always report 0. A POST failure is reported by the indicator LED’s. A self-reset will be attempted following the error report.

0x2000

1.3.6.1.4.1.2680.1.1.3.1

Integer

Read-only

2.1.0

errorIndicators

This value is a sum of exclusive binary values which can be OR’d to represent multiple errors. 0x01 - Fault 0x04 - Receive error 0x08 - Transmit error 0x10000 - Audio mute (audio output may be corrupt) 0x20000 - BuddyLink output disabled (fault or lost contact with the network) 0x40000 - Unexpected system error (diagnostic information on firmware fault may be available in errorDisplay)

Host Address

SNMP Object ID

Type

Attributes

Implemented Version

Name

Description

Host Address

SNMP Object ID

Type

Attributes

Default Value

0x2001

1.3.6.1.4.1.2680.1.1.3.2

Integer

Read-only

2.1.0

errorCode

Last error code reported. On 24-bit platforms, error code is a byte in MS byte position of this variable. On 32-bit platforms, error code is a byte in LS byte position of this variable. Some values are warnings and will not affect errorIndicators. See error table. Note: this variable has also been referred to as errorLast in older documentation and MIB files.

0x2002

1.3.6.1.4.1.2680.1.1.3.3

Integer

Read-only

Implemented Version

2.1.0

CobraNet Programmer’s Reference

Management Interface Variable Reference

Name

Description

Host Address

SNMP Object ID

Type

Attributes

Default Value

Implemented Version

Name

Description

Host Address

SNMP Object ID

Type

errorCount

Number of errors reported during sysUpTime. Some errors are warnings and do not affect errorIndicators.

0x2003

1.3.6.1.4.1.2680.1.1.3.4

Counter

Read-only

2.1.0

errorDisplay

Error code to display on a user interface. Error codes are displayed for serious and unexpected error conditions. A value of 0 indicates there is no error code to display.

0x2004

1.3.6.1.4.1.2680.1.1.3.5

Integer

Attributes

Default Value

Implemented Version

Name

Description

Host Address

SNMP Object ID

Type

Attributes

Implemented Version

Read-only

2.1.0

modeRateStatus

Indicates the latency and sample rate operating mode currently in effect for the interface.

modeRateStatus and modeRateControl will differ if an unsupported mode value is written to modeRateControl

0x2005

1.3.6.1.4.1.2680.1.1.3.6.2

Integer

Read-only

2.9.0

CobraNet Programmer’s Reference

Management Interface Variable Reference

Name

Description

Host Address

SNMP Object ID

Type

Attributes

Default Value

Implemented Version

modeRateControl

Selects latency and sample rate mode for the interface. The following modes are supported: 0x701 - 5-1/3 ms latency, 96 kHz sample rate 0x600 - 5-1/3 ms latency, 48 kHz sample rate 0x601 - 2-2/3 ms latency, 96 kHz sample rate 0x500 - 2-2/3 ms latency, 48 kHz sample rate 0x501 - 1-1/3 ms latency, 96 kHz sample rate 0x400 - 1-1/3 ms latency, 48 kHz sample rate

0x2100

1.3.6.1.4.1.2680.1.1.3.6.1

Integer

Read/write - Persistent

0x600

2.9.0

6.4.5 Conductor

These variables determine the values transmitted in the header of the Beat Packet when the CobraNet interface is acting as the network conductor.

CobraNet Programmer’s Reference

Management Interface Variable Reference

Name

Description

Host Address

SNMP Object ID

Type

Attributes

Default Value

Implemented Version

Name

Description

Host Address

conductorCycleRate

Number of isochronous cycles per second as a 16.16 fixed point number. This is a legacy variable. It always reports default value and should not be changed.

0x10000

1.3.6.1.4.1.2680.1.1.4.1

Integer48

Read/write - Persistent

750

2.2.0

conductorPriority

Specifies the conductor priority for a CobraNet device. The device with the highest priority will become the conductor for the network. MS byte must be 0. 0 - Never Conduct 0x1 - Lowest conductor priority 0xFF - highest conductor priority

0x10002

SNMP Object ID

Type

Attributes

Default Value

Implemented Version

1.3.6.1.4.1.2680.1.1.4.2

Integer16

Read/write - Persistent

0x20 for reference design, 0x30 for CM-1, CS4961xx, and CS1810xx.

2.2.0

CobraNet Programmer’s Reference

Management Interface Variable Reference

Name

Description

Host Address

SNMP Object ID

Type

Attributes

Default Value

Implemented Version

Name

Description

conductorGaps

These timing specifications are applicable only to repeater networks and therfore do not apply to most CobraNet applications. This variable is changed on the active conductor in order to reduce the probability of collisions. In most cases the default value works well. Useful values other than the default are dependant on the specific network topology used. Channel Gap in LS byte - Larger channel gaps allow greater network diameter. Packet Gap in MS byte - Larger packet gaps increase resilience to unregulated traffic.

0x10003

1.3.6.1.4.1.2680.1.1.4.3

Integer16

Read/write - Persistent

0x0306

2.2.0

conductorStatus

Conductor status: 0 - This interface is not the conductor 1 - This interface is the conductor

Host Address

SNMP Object ID

Type

Attributes

Implemented Version

0x11000

1.3.6.1.4.1.2680.1.1.4.4

Integer

Read-only

2.1.0

6.4.6 Conductor Information

These conductor variables give a description and status of the current conductor of the CobraNet network.

CobraNet Programmer’s Reference

Management Interface Variable Reference

Name

Description

Host Address

SNMP Object ID

Type

Attributes

Implemented Version

Name

Description

Host Address

condInfoPriority

Conductor priority of the current conductor. 1 - Lowest conductor priority 255 - highest conductor priority If the priority of the current conductor is adjusted, condInfoPriority will change to reflect this. Dependent on priority setting of other devices on the network, a change in current conductor priority does not necessarily induce a change in conductor and condInfoMAC.

0x11001

1.3.6.1.4.1.2680.1.1.4.5

Integer

Read-only

2.9.12 (24-bit platforms only.) Not available on 32-bit patforms.

condInfoMAC

Ethernet MAC address of the current conductor. condInfoMAC should read 00:00:00:00:00:00 if there is no conductor on the network. There is no conductor if there is 0 or 1 CobraNet device(s) attached to the network or if all CobraNet devices have a condPriority setting of 0.

0x11002

SNMP Object ID

Type

Attributes

Implemented Version

Name

Description

Host Address

SNMP Object ID

Type

Attributes

Implemented Version

1.3.6.1.4.1.2680.1.1.4.6

Physical Address

Read-only

2.9.12 (24-bit platforms only.) Not available on 32-bit patforms.

condInfoLastChange

sysUpTime value at time of last change to condInfoMAC.

0x11005

1.3.6.1.4.1.2680.1.1.4.7

Time Ticks

Read-only

2.9.12 (24-bit platforms only.) Not available on 32-bit patforms.

CobraNet Programmer’s Reference

Management Interface Variable Reference

Name

Description

Host Address

SNMP Object ID

Type

Attributes

Implemented Version

condInfoChanges

Count of condInfoMAC changes since boot. A single conductor arbitration event may produce multiple increments.

0x11007

1.3.6.1.4.1.2680.1.1.4.8

Counter

Read-only

2.9.12 (24-bit platforms only.) Not available on 32-bit patforms.

6.4.7 Packet Bridge

CobraNet Programmer’s Reference

Management Interface Variable Reference

Name

Description

Host Address

SNMP Object ID

Type

Attributes

Default Value

Implemented Version

Name

Description

bridgeTxPkt

Variable is used in conjunction with bridgeTxDone. If bridgeTxPkt and bridgeTxDone are equal, then it is permitted to write new packet data to bridgeTxPktBuffer. Setting bridgeTxPkt different than bridgeTxDone will cause the contents of the packet buffer to be transmitted. Upon transmit completion, bridgeTxDone will be updated to match bridgeTxPkt. Packet transmission can also be initiated by issuing a Packet Transmit command via HMI.

0x20000

Not available via SNMP

Integer

Read/Write

2.2.0

bridgeRxPkt

This variable is used in conjunction with bridgeRxReady. If values of bridgeRxPkt and bridgeRxReady differ, then bridgeRxPktBuffer contains received data and may be read by the host. Setting bridgeRxPkt equal to bridgeRxReady will release the buffer to the CobraNet interface so that the next packet can be received.

Host Address

SNMP Object ID

Type

Attributes

Default Value

Implemented Version

Name

Description

Host Address

SNMP Object ID

Type

Attributes

0x20001

Not available via SNMP

Integer

Read/Write

2.2.0

bridgeMMAC

Specifies the source multicast MAC address of packets to be received via the packet bridge. To receive multicast addressed packets, it is necessary to compute and load a multicast hash filter table into bridgeHashBuffer.

0x20002 - 0x20004

Not available via SNMP

PhysAddress

Read/Write

Default Value

Implemented Version

00:00:00:00:00:00

2.2.0

CobraNet Programmer’s Reference

Management Interface Variable Reference

Name

Description

Host Address

SNMP Object ID

Type

Attributes

Default Value

Implemented Version

Name

Description

Host Address

bridgeCalcMMACHash

This variable is used to calculate a hash value based on the address in bridgeMMAC. Writing a value different than bridgeMMACHashDone to this variable causes the calculation to begin. When complete, bridgeMMACHashDone will be updated with the value written here and

bridgeMACHashBuf will contain the new hash value. Folding bridgeMACHashBuf resuls into bridgeHashBuf will then allow receipt of packets from the multicast address specified in bridgeMMAC.

0x20005

Not available via SNMP

Integer

Read/Write

2.2.0

bridgeMMACHashBuffer

This is the calculated hash value for the MAC address entered in bridgeMMAC.

0x20006 - 0x20009

SNMP Object ID

Size

Type

Attributes

Default Value

Implemented Version

Name

Description

Host Address

SNMP Object ID

Size

Type

Attributes

Not available via SNMP

4 words

Octet String

Read/Write

2.2.0

bridgeHashBuffer

This is the value loaded to the hash table of the Ethernet controller which determines the range of multicast addresses the host will receive.

0x2000A - 0x2000D

Not available via SNMP

4 words

Octet String

Read/Write

Default Value

Implemented Version

2.2.0

CobraNet Programmer’s Reference

Management Interface Variable Reference

Name

Description

Host Address

SNMP Object ID

Type

Attributes

Default Value

Implemented Version

Name

Description

bridgeRxFilter

Selects which types of received packets will be passed to the host via the packet bridge. The following values may be ORed together. See Figure 4 on page 15. 0x1 - bridge unprocessed CobraNet packets

0x2

- bridge all CobraNet reservation packets

0x8

- bridge all IP packets (IP, ARP and RARP)

0x10 - bridge all packets with unknown protocol identifier

Copies of packets are passed to the packet bridge and the originals are still processed by the

CobraNet interface. Care must be taken that redundant replies are not generated.

0x2000E

Not available via SNMP

Integer

Read/Write

2.6.9

bridgeTxPktBuffer

Buffer for bridge packet transmission. The first word contains the length of the packet in bytes exclusive of the length field itself. Ethernet packet data, including complete header and payload, follows the length. The FCS field is computed and appended by the Ethernet controller and is not included as part of the packet data or length. See Section 2.2 "Packet Bridge" on page 13 for more information on the format and use of this buffer

Host Address

SNMP Object ID

Count

Type

Attributes

Implemented Version

0x21000

Not available via SNMP

758 on 24-bit platforms, 380 on 32-bit platforms.

Integer16

Read/Write

2.2.0

CobraNet Programmer’s Reference

Management Interface Variable Reference

Name

Description

Host Address

SNMP Object ID

Count

Type

Attributes

Implemented Version

Name

Description

Host Address

SNMP Object ID

Type

bridgeRxPktBuffer

Buffer to read received packet. The data format for packet data is the same as used in bridgeTxPktBuffer.

0x22000

Not available via SNMP

1 + actual packet size in words.

Integer16

Read/Write

2.2.0

bridgeTxDone

Please refer to bridgeTxPkt documentation. This variable is used in conjunction with bridgeTxPkt.

0x23000

Not available via SNMP

Integer

Attributes

Default Value

Implemented Version

Name

Description

Host Address

SNMP Object ID

Type

Attributes

Default Value

Implemented Version

Read-only

2.2.0

bridgeRxReady

Please refer to bridgeRxPkt documentation. This variable is used in conjunction with bridgeRxPkt.

0x23001

Not available via SNMP

Integer

Read-only

2.2.0

CobraNet Programmer’s Reference

Management Interface Variable Reference

Name

Description

Host Address

SNMP Object ID

Type

Attributes

Default Value

Implemented Version

Name

Description

Host Address

SNMP Object ID

bridgeMMACHashDone

Refer to bridgeCalcMMACHash documentation. This variable is used in conjunction with bridgeCalcMMACHash.

0x23002

Not available via SNMP

Integer

Read-only

2.2.0

bridgeRxDropped

Counts the number of received packet bridge packets dropped due to the receive buffer being unavailable. Packets which could be received via the packet bridge will be dropped if the host has ownership of the receive buffer (bridgeRxPktBuffer).

0x23003

Not available via SNMP

Type

Attributes

Default Value

Implemented Version

Counter

Read-only

2.5.7

CobraNet Programmer’s Reference

Management Interface Variable Reference

6.4.8 Serial Bridge

Name

Description

Host Address

SNMP Object ID

serialFormat

This variable is used to enable or disable the Serial Communications Interface (a.k.a SCI or Serial Bridge) and to set the data format for both transmit and receive directions. Format may only be changed while the SCI is disabled (LS bit = 0). It is recommended to set serialFormat to 0, wait at least 100ms then set serialFormat to the desired value with the enable bit set. The SCI can take up to 100ms to recognize a change.This procedure insures that the change is recognized and the port is properly configured. The following values may be OR’d together:

0x01 - Enable serial bridging. TXD pin is tri-stated when disabled. 0x02 - Use nine-bit data format. The 9th data bit is bridged over the Ethernet along with the

standard 8 data bits. 9 bit format is appropriate for the following standard serial data formats: N,9,1 E,8,1 O,8,1 M,8,1 S,8,1 N,7,2. The 8 bit data format supports the following standard serial data formats: N,8,1 E,7,1 O,7,1 M,7,1 S,7,1. If the 8th or 9th bit is used as a parity bit, it is simply bridged across the network and must be generated and/or checked by the device connected to the bridge interface. CS4961xx- and CS1810xx

ignored.

0x04 - Use SCI_SCLK to control transmit enable for multi-drop (RS485) operation. SCI_SCLK is an active high signal; transmitter should be enabled when SCI_SCLK is high.

CS4961xx and CS1810xx firmware does not currently support tri-state control format; this bit is ignored.

0x08 - Enable local loopback. This feature is intended primarily for factory test. SCI bridging must also be enabled for loopback to operate. When loopback is enabled, received characters are directed to the SCI transmitter instead of to the network. serialRxMAC should be set to 00:00:00:00:00:00 to avoid transmitter contention when loopback is enabled. 0x10 - Accept properly unicast addressed data in addition to data addressed in accordance to serialRxMAC setting.

0x24000

1.3.6.1.4.1.2680.1.1.10.1.1

-based hardware does not support 9-bit format; this bit is

Type

Attributes

Default Value

Implemented Version

Name

Description

Host Address

SNMP Object ID

Type

Attributes

Default Value

Implemented Version

Integer

Read/write - Persistent

2.4.7. Available via SNMP in 2.6.4. Accept unicast (0x10 bit) implemented in 2.8.8.

serialBaud

Baud rate for transmission and reception. The baud rate is specified in bits per second. The minimum baud rate is 600 baud. Maximum baud rate is 57,600. CS4961xx- and CS1810xx-based interfaces will support baud rates up to 115,200

0x24001

1.3.6.1.4.1.2680.1.1.10.1.2

Integer

Read/write - Persistent

19200

2.4.7 (available via SNMP in 2.6.4)

CobraNet Programmer’s Reference

Management Interface Variable Reference

Name

Description

Host Address

SNMP Object ID

Type

Attributes

Default Value

Implemented Version

serialPPeriod

Time in 256ths of a millisecond before a character received at the SCI port is placed in a packet and transmitted. Shorter periods to achieve lower latency are appropriate for real time connections such as MIDI. With higher settings more characters can be packed into a packet before it is transmitted resulting in increased efficiency. Higher settings are recommended for bulk data transfer applications. The isochronous cycle period (1-1/3 mS) determines the minimum serialPPeriod. Setting serialPPeriod below the isochronous cycle rate does not further improve responsiveness. The upper limit of responsiveness can also affected by control channel accessibility and pipeline delays. The depth of the receive SCI character queue in combination with the baud rate determines the maximum allowed setting. The character buffer can accommodate 100 characters. This allows for operation at the default 10ms period at a baud rate of 57,600. At this baud rate, larger settings will result in buffer overflow and loss of data.

0x24002

1.3.6.1.4.1.2680.1.1.10.1.3

Integer

Read/write - Persistent

2560 (10ms)

2.4.7 (available via SNMP in 2.6.4)

Name

Description

Host Address

SNMP Object ID

Type

Attributes

Default Value

Implemented Version

serialRxMAC

MAC address of the CobraNet Interface from which SCI data will be accepted. This may be any multicast address though 01:60:2B:FD:00:00 through 01:60:2B:FD:FF:FF have been reserved by Cirrus Logic for use as "asynchronous global channels." ifPhysAddress is the only usable unicast address (CobraNet does not support Ethernet promiscuous mode).

0x24003

1.3.6.1.4.1.2680.1.1.10.1.4

PhysAddress

Read/write - Persistent

01:60:2B:FD:00:00

2.4.7 (available via SNMP in 2.6.4)

CobraNet Programmer’s Reference

Management Interface Variable Reference

Name

Description

Host Address

SNMP Object ID

Type

Attributes

Default Value

Implemented Version

Name

Description

serialTxPriority

Serial bridging bundle priority in MS byte. Higher priority bundles are transmitted earlier in the isochronous cycle and are thus less susceptible to dropouts in the event network bandwidth is exhausted. Request priority in LS byte. Contention for transmission on a bundle is resolved via request priority. This variable has no effect when serialTxBundle is 0.

The reference design, CM-1,CM-2, CS4961xx, and CS1810xx isochronous transmission of serial data and ignore settings for serialTXBundle and serialTxPriority.

0x24006

1.3.6.1.4.1.2680.1.1.10.1.5

Integer16

Read/write - Persistent

0x0110

2.4.7 (available via SNMP in 2.6.4)

serialTxBundle

On legacy repeater Ethernet networks and CobraNet interface hardware, serialTXBundle is used to specify a bundle number for use in transmitting serial data reliably over CobraNet's isochronous audio transport service. Specifying bundle 0 causes serial data to be delivered normally via the asynchronous transport. This is the default and recommended setting.

The reference design, CM-1,CM-2, CS4961xx- and CS1810xx isochronous transmission of serial data and ignore settings for serialTXBundle and serialTxPriority.

-based designs do not support

Host Address

SNMP Object ID

Type

Attributes

Default Value

Implemented Version

Name

Description

Host Address

SNMP Object ID

Type

Attributes

Default Value

0x24007

1.3.6.1.4.1.2680.1.1.10.1.6

Integer16

Read/write - Persistent

2.4.7 (available via SNMP in 2.6.4)

serialTxMAC

MAC address of the CobraNet interface to which serial data is sent. May be any multicast or unicast address.

0x24100

1.3.6.1.4.1.2680.1.1.10.1.7

PhysAddress

Read/write - Persistent

01:60:2B:FD:00:00

Implemented Version

2.4.7 (available via SNMP in 2.6.4)

6.4.9 Interrupt Control

CobraNet Programmer’s Reference

Management Interface Variable Reference

Name

Description

Host Address

SNMP Object ID

Type

Attributes

Default Value

Implemented Version

Name

Description

hackEnable

Enable conditions for asserting HACK. HACK is de-asserted by issuing an Interrupt Acknowledge HMI command. The following values may be OR’ed together

0x4 - Activate HACK on bridge packet receipt (change in bridgeRxReady). 0x8 - Activate HACK on bridge packet transmission complete (change in bridgeTxDone). 0x10 - Activate HACK on HMI address translation completion (change in hackTranslations). 0x20 - Activate HACK on MI variable change via SNMP (change in miMonSNMPDirty or

hackSNMPModify).

0x40 - Enable HACK Timer.

0x25000

Not available via SNMP

Integer

Read/Write

2.10.4 for CS18101-based formware only.

hackTimerInterval

A mask defining which bits of the network time should be locked to generate a HACK timer interrupt. The hackTimerInterval variable will be limited to powers of 2, in units of isochronous cycle intervals. The isochronous cycle interval is 1-1/3 ms. The correct mask value will be a power of 2 minus one. For example, a value of 0xffff will generate an interrupt every 256*1-1/3 = 341.33 ms.

Host Address

SNMP Object ID

Type

Attributes

Default Value

Implemented Version

0x25001

Not available via SNMP

Integer32

Read/Write

0xffffffff

2.10.4 for CS18101-based firmware only.

CobraNet Programmer’s Reference

Management Interface Variable Reference

Name

Description

Host Address

SNMP Object ID

Type

Attributes

Implemented Version

Name

Description

Host Address

hackStatus

Indicates the source of a HACK assertion requiring acknowledge. The following values may be OR’d together. Undocumented bits should be ignored: 0x01 - A new receive packet is available in the receive buffer. Host should read packet data from receive buffer and then acknowledge receipt. 0x02 - No transmission in progress. Host may write transmit packet data into the transmit buffer. On 32-bit platforms, these bits may also be read in the HMI status register Received packet available and Packet transmission complete.

0x25100

Not available via SNMP

Integer

Read-only

2.8.5

hackTranslations

Incremented when a translate address command completes. On 32-bit platforms, this information is also available through the Translation Complete bit in the HMI status register.

0x25101

SNMP Object ID

Type

Attributes

Implemented Version

Name

Description

Host Address

SNMP Object ID

Type

Attributes

Implemented Version

Not available via SNMP

Counter

Read-only

2.8.5

hackSNMPModify

Copy of miMonSNMPDirty.

0x25102

Not available via SNMP

Counter

Read-only

2.8.5

CobraNet Programmer’s Reference

Management Interface Variable Reference

Name

Description

Host Address

SNMP Object ID

Type

Attributes

Implemented Version

Name

Description

Host Address

hackReadLength

Size of readable area in words for the last address traslation. 0 if read permission is denied (invalid address). This variable is updated upon completion of a translate address operation. On 32-bit platforms, this information is also available through the Region length field in the status register.

0x25103

Not available via SNMP

Integer

Read-only

2.8.5

hackWriteLength

Size of writable area in words for the last address traslation. 0 if write permission is denied (invalid address or read only region). This variable is updated upon completion of a translate address operation. On 32-bit platforms, this information is also available through the Region length field in the status register.

0x25104

SNMP Object ID

Type

Attributes

Implemented Version

Name

Description

Host Address

SNMP Object ID

Type

Attributes

Implemented Version

Not available via SNMP

Integer

Read-only

2.8.5

hackNTime

CobraNet network time - a copy of syncNTime. CS4961xx and CS1810xx only.

0x25105

Not available via SNMP

Integer

Read-only

2.9.9 (2.10.4 for CS18101-based firmware)

CobraNet Programmer’s Reference

Management Interface Variable Reference

6.4.10 Audio

Name

Description

Host Address

SNMP Object ID

Type

Attributes

Default Value

Implemented Version

Name

Description

Host Address

audioMeterDropouts

This counter is incremented each isochronous cycle that metering is not performed. Metering may be skipped when processor cycles are in high demand on the interface.

0x30000

1.3.6.1.4.1.2680.1.1.5.1

Counter

Read-only

2.2.0

audioAllowedChannels

Number of audio channels this CobraNet interface is licensed to handle. AudioAllowedChannels <

audioRxChannels + audioTxChannels indicates a licensing violation. There are not implemented. On CS4961xx and CS1810xx, audioAllowedChannels, audioRxChannels and audioTxChannels always read 0.

0x30001

NO license fees on CS4961xx- and CS1810xx-based interfaces. Channel accounting is

SNMP Object ID

Type

Attributes

Default Value

Implemented Version

Name

Description

Host Address

SNMP Object ID

Type

Attributes

Default Value

Implemented Version

1.3.6.1.4.1.2680.1.1.5.6

Integer

Read-only

Read from flash configuration record.

2.8.3.

audioRxChannels

Number of unique audio channels currently being received from the network.

On CS4961xx- and CS1810xx

0x30002

1.3.6.1.4.1.2680.1.1.5.7

Integer

Read-only

2.8.3.

-based interfaces this variable always reads 0.

CobraNet Programmer’s Reference

Management Interface Variable Reference

Name

Description

Host Address

SNMP Object ID

Type

Attributes

Default Value

Implemented Version

Name

Description

audioTxChannels

Number of unique audio channels currently being transmitted to the network.

On CS4961xx and CS1810xx this variable always reads 0.

0x30003

1.3.6.1.4.1.2680.1.1.5.8

Integer

Read-only

2.8.3.

audioMeterDecay

Decay time constant for audioMeters. Meters have an instantaneous attack time that cannot be adjusted. This constant can be computed from the desired decay time (t) as:

24-bit platforms: 0x800000×((1-tan(1/(1500×t)))/(1+tan(1/(1500*t)))) 32-bit platforms: 0x80000000×((1-tan(1/(1500×t)))/(1+tan(1/(1500*t))))

For reasonably large decay times (>50ms) this can be approximated as:

24-bit platforms: 0x800000×(((1500×t)-1)/((1500×t)+1)) 32-bit platforms: 0x80000000×(((1500×t)-1)/((1500×t)+1))

Example decay settings: 0 - Instantaneous 8170671 (0x7CACAF) 24-bit, 2091691776 (0x7CACAF00) 32-bit - 50ms 8333053 (0x7F26FD) 24-bit, 2133261568 (0x7F26FD00) 32-bit - 200ms 8377430 (0x7FD456) 24-bit, 2144622080 (0x7FD45600) 32-bit - 1 second 8388235 (0x7FFE86) 24-bit, 2147388160 (0x7FFE8600) 32-bit - 30 seconds

Host Address

SNMP Object ID

Type

Attributes

Default Value

Implemented Version

0x30100

1.3.6.1.4.1.2680.1.1.5.5

Integer

Read/write - Persistent

2.6.9

CobraNet Programmer’s Reference

Management Interface Variable Reference

Name

Description

Host Address

SNMP Object ID

Count

Type

Attributes

Default Value

Implemented Version

Name

Description

audioMeterMap

Maps audio routing channels to audio metering. Meters 0-31 are designated for metering audio inputs. Meters 32-63 are designated for metering outputs. The first unassigned (null or unconnected routing channel) in each section terminates meter processing. It is not possible to activate meter 3 without first activating meter 2, for instance.

0x31000

1.3.6.1.4.1.2680.1.1.5.2.1.2

Integer

Read/write - Persistent

2.2.0

audioMeterPeaks

The peak level is the highest level recorded since the last time the meters were reset. Level is represented as a 24- of 32-bit positive value. 0 indicating the absence of signal and 0x7FFFFF or 0x7FFFFFFF indicating a full-scale signal. Reset is accomplished by writing 0 to the peak level. It is not possible to determined if a peak level is missed between the time the variable is read and when it is cleared. Also it should be recognised that it is possible for another manager to clear this variable. There is no way of determining when this has happened.

Host Address

SNMP Object ID

Count

Type

Attributes

Default Value

Implemented Version

0x32000

1.3.6.1.4.1.2680.1.1.5.2.1.3

Integer

Read/write

2.1.0

CobraNet Programmer’s Reference

Management Interface Variable Reference

Name

Description

Host Address

SNMP Object ID

Count

Type

Attributes

Implemented Version

Name

Description

Host Address

audioMeters

Allows reading current audio levels. Ballistics for metering comprise an instantaneous attack and exponential decay time programmable via audioMeterDecay. All level measurements are peak level (as opposed to RMS). Level is reported as a 24- or 32-bit positive value. 0 indicates the complete absence of signal and 0x7FFFFF or 0x7FFFFFFFF indicates a full-scale signal.

0x33000

1.3.6.1.4.1.2680.1.1.5.2.1.4

Integer

Read-only

2.1.0

audioMeterPeakRaw

Efficiently retrieves all audioMeterPeaks values in a single Get operation. On 24-bit platforms, audioMeterPeakRaw and audioMeterRaw values are packed in 3 octet words. On CS4961xx- and CS1810xx-based platforms the values are packed in 4 octet words. Byte ordering for 24-bit platforms is MS, Middle, LS. Byte ordering for 32-bit platforms is MS, Middle High, Middle Low, LS.

0x32000

SNMP Object ID

Count

Type

Attributes

Default Value

Implemented Version

1.3.6.1.4.1.2680.1.1.5.2.1.5

Integer

Read/write

2.9.3 (24-bit platforms), 2.10.4 (32-bit paltforms)

CobraNet Programmer’s Reference

Management Interface Variable Reference

Name

Description

Host Address

SNMP Object ID

Count

Type

Attributes

Default Value

Implemented Version

Name

Description

audioMeterRaw

Efficiently retrieves all audioMeters values in a single Get operation. On 24-bit platforms, audioMeterPeakRaw and audioMeterRaw values are packed in 3 octet words. On CS4961xx- and CS1810xx-based platforms the values are packed in 4 octet words. Byte ordering for 24-bit is MS, Middle, LS. Byte ordering for 32-bit platforms is MS, Middle High, Middle Low, LS.

0x32000

1.3.6.1.4.1.2680.1.1.5.2.1.6

Integer

Read/write

2.9.3 (24-bit platforms), 2.10.4 (32-bit paltforms)

audioLoopSrc

Describes source audio routing channels for performing a local audio loopback function. The first unassigned (null or unconnected routing channel) loopback entry terminates loopback processing. It is not possible to activate loopback element 3 without first activating loopback 2, for instance.

Host Address

SNMP Object ID

Count

Type

Attributes

Default Value

Implemented Version

0x34000

1.3.6.1.4.1.2680.1.1.5.3.1.2

8 in standard firmware build.

Integer

Read/write - Persistent

2.1.0

CobraNet Programmer’s Reference

Management Interface Variable Reference

Name

Description

Host Address

SNMP Object ID

Count

Type

Attributes

Default Value

Implemented Version

Name

Description

Host Address

audioLoopDst

Describes destination audio routing channels for performing a local audio loopback function. See audioLoopSrc for a complete description.

0x35000

1.3.6.1.4.1.2680.1.1.5.3.1.3

8 in standard firmware build

Integer

Read/write - Persistent

2.1.0

audioOutputs

List of audio output routing channels. Audio output data must be cleared to silence if data is not received over the network for the channels. By default 33 - 64 are used as outputs but these variables may be configured by the manufacturer according to the audio I/O configuration of the hardware. The user should not change these values.

0x36000

SNMP Object ID

Count

Type

Attributes

Default Value

Implemented Version

1.3.6.1.4.1.2680.1.1.5.4.1.2

Integer

Read/write - Persistent

{33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64}

2.1.0

CobraNet Programmer’s Reference

Management Interface Variable Reference

Name

Description

Host Address

SNMP Object ID

Count

Type

Attributes

Default Value

Implemented Version

Name

Description

audioMap

Audio routing channel to synchronous serial audio channel mapping. Each entry specifies an SSI audio buffer offset corresponding to a routing channel. The first audioMap entry corresponds to routing channel 1. These variables are configured by the manufacturer according to the audio I/O configuration of the hardware. Cirrus Logic can assist manufacturers in determining proper configuration of these variables to match audio I/O hardware. The user should not change these values.

0x37000

1.3.6.1.4.1.2680.1.1.5.2.1.5

Integer

Read/write - Persistent

Product specific

2.1.0

audioDupSrc

A vector used to specify the source audio routing channels used in audio channel duplication. Each audioDupSrc vector member will have a corresponding audioDupDst member corresponding to each available duplication channel. AudioDupSrc will contain the source audio routing channel number and audioDupDst will contain the corresponding destination audio routing channel. The audio routing channel chosen as either a source or destination must be an output channel (i.e. appear in audioOutputs which, by default, consists of audio routing channels 33-64). The first unassigned entry (null or unconnected routing channel for either source or destination) terminates dup processing. For instance, it is not possible to specify dup channel 3 without first specifying dup channel 2.

Host Address

SNMP Object ID

Count

Type

Attributes

Implemented Version

0x38000

1.3.6.1.4.1.2680.1.1.5.9.1.2

0 in standard CM-1 firmware, 8 in CS4961xx and CS1810xx firmware.

Integer

Read/Write

2.8.5

CobraNet Programmer’s Reference

Management Interface Variable Reference

Name

Description

Host Address

SNMP Object ID

Count

Type

Attributes

Implemented Version

Name

Description

Host Address

audioDupDst

A vector used to specify the source audio routing channels used in audio channel duplication. See audioDupSrc.

0x39000

1.3.6.1.4.1.2680.1.1.5.9.1.3

0 in standard CM-1 firmware, 8 in CS4961xx and CS1810xx firmware.

Integer

Read/Write

2.8.5

audioMeterPeaksRaw

Efficiently retrieve all audioMeterPeaks values in a single Get operation. 24-bit platforms: values are packed in 3 octet words. Byte ordering is Most Significant, Middle, Least Significant. 32-bit platforms: values are packed in 4 octet words. Byte ordering is Most Significant, Middle High, Middle Low, Least Significant.

Not available via HMI

SNMP Object ID

Type

Attributes

Implemented Version

Name

Description

Host Address

SNMP Object ID

Type

Attributes

Implemented Version

1.3.6.1.4.1.2680.1.1.5.10

Octet string

Read-only

2.9.3, 2.10.5

audioMetersRaw

Efficiently retrieve all audioMeters values in a single Get operation. 24-bit platforms: values are packed in 3 octet words. Byte ordering is Most Significant, Middle, Least Significant. 32-bit platforms: values are packed in 4 octet words. Byte ordering is Most Significant, Middle High, Middle Low, Least Significant.

Not available via HMI

1.3.6.1.4.1.2680.1.1.5.11

Octet string

Read-only

2.9.3, 2.10.5

CobraNet Programmer’s Reference

Management Interface Variable Reference

Name

Description

Host Address

SNMP Object ID

Type

Attributes

Implemented Version

audioSSIFormat

Format of SSI channel data.

0 - Normal Mode 1 - I2S Mode 2 - Standard Mode

Default is Normal Mode

See Hardware User's Manual for SSI mode descriptions.

0x30004

1.3.6.1.4.1.2680.1.1.5.12

Integer

Read-only

2.9.10, 2.10.5

Cirrus Logic CobraNet User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual

Features

General Description

Table of Contents

1. Overview

1.1 CobraNet Terminology

1.2 Protocol

1.2.1 Beat Packet

1.2.2 Isochronous Data Packet (or Bundle)

1.2.3 Reservation Packet

1.2.4 Serial Bridge Packet

1.3 Timing and Performance

1.4 Bundle Addressing types

2. Control Communications

2.1 Serial Bridge

2.2 Packet Bridge

2.2.1 Packet Bridge Buffer Data Format

2.2.2 Packet Bridge Receive Filtering

3. Network Stack

3.1 CobraNet Audio

3.2 Serial Bridge

3.3 Packet Bridge

3.4 BOOTP

3.5 RARP (partial support)

3.6 ICMP (partial support)

3.7 ARP

3.8 IP

3.9 UDP

3.10 TFTP

3.11 SNMP

4. Audio Paths

4.1 Audio Routing Channels

4.2 Bundle Transmitters

4.3 Bundle Receivers

4.4 Loopback

4.5 Output Channel Duplication

4.6 Meters

4.7 Low-latency Audio Support

4.8 96 kHz Sample Rate Support

5. Management Interface

5.1 Flash

5.2 Persistence

5.3 Watch Dog

5.4 SNMP Extension Agent

6. Management Interface Variable Reference

6.1 Legend

6.2 Data Types

6.2.1 DisplayString

6.2.2 OID

6.2.3 IpAddress

6.2.4 PhysAddress

6.2.5 TimeTicks

6.2.6 Counter

6.2.7 Counter2

6.2.8 Integer

6.2.9 Integer16

6.2.10 Integer48

6.3 MIB-II Variables

6.3.1 System

6.3.2 Interface

6.3.3 Address Translation

6.3.4 IP

6.3.5 UDP

6.3.6 SNMP

6.4 CobraNet Variables

6.4.1 Firmware

6.4.2 Hardware Identification

6.4.3 Flash

6.4.4 Errors

6.4.5 Conductor

6.4.6 Conductor Information

6.4.7 Packet Bridge

6.4.8 Serial Bridge

6.4.9 Interrupt Control

6.4.10 Audio