User guide

CobraNet Programmer’s Reference

Management Interface

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.

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

Byte 3 Byte 2 Byte 1

Second Word

Byte 6 Byte 5 Byte 4