User guide

CobraNet Programmer’s Reference
Management Interface
DS651PM25 ©Copyright 2006 Cirrus Logic, Inc. 27
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.
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.