How to Manage
User Manual for AZ430 WAN Satellite Modem
4.3.5 Protocol
The control unit sends a “request” message to a device identified by its unique
address. The addressed device interprets the message, performs the requested
action and sends a “response” message back.
The receiving device rejects all messages with transmission errors without any
further action. Transmission errors are:
•
No stop bit
•
Parity
error
•
LRC-error
•
Message receive buffer overflow.
The addressed device responds to all correct formatted messages – except for
some special system messages – with an acknowledge message. Only in a few
restricted cases does the device not respond to a request from the control unit.
This is, for example, the case when a general device reset is requested.
Correctly received messages which the device cannot handle are refused via a no-
acknowledge “error” message. This message contains the reason why the
message is rejected.
A device never sends messages on its own initiative. It only responds to a request
from the control unit. The total transmit time of a complete message may not
exceed 250 ms. If the message is not completed within this time, it is discarded.
4.4 SNMP
The Newtec MIB allows full monitor and control over the complete device using any
SNMP browser (HP-OpenView, NetworkView). We support the basic standard MIB
(monitor and control of IP interface, versions of the software …) and above that we
have a full proprietary MIB, which contains all the OIDs needed to control the
device.
We support traps. These form a mechanism to trigger the NMS when a change in
the device has occurred. After receiving the trap the NMS still has to poll the device
to find out the details of the change.
The SNMP details can be found in the reference manual of this
modem.
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SHAPING THE FUTURE OF SATELLITE COMMUNICATIONS
