Airmar PB200 - Manual (Page 16)

PB200 WeatherStation User Manual revision 1.000
Proprietary and Confidential
10
NMEA 2000® TRANSMITTED PARAMETER GROUP
PGN
065287
(0x0FF07)
Proprietary: Access Level
Single Frame: Yes Priority: 7/Y/N Update Rate: 0/N/N Destination: Global Query Support: Yes Access Level: 0
Field
#
Name
Request
Param. DD
DF Type Resolution Value Remark
1 Manufacturer Code Yes DD172 DF52 11 bits 1 135 (decimal) Manufacturer Code for Airmar Technology.
2 Reserved bits No DD001 DF52 2 bits 1 0x3 All bits set to logic "1"
3 Industry Group Yes DD168 DF52 3 bits 1 4 (decimal) Industry Group for "Marine Industry".
4 Format Code Yes DD005 DF53 uint8 1 bit 1 1 = Format Code 1
5 Access Level No N/A DF52 3 bits 1 0x0 = locked
0x1 = unlocked, level 1
0x2 = unlocked, level 2
0x3 to 0x7 = reserved When this PGN is transmitted, this field
indicates the current Access Level of the PB200.
This field may be changed using the Command
Group Function PGN 126208 (see text below).
6 Reserved bits No DD001 DF52 5 bits 1 0x1F All bits set to logic "1"
7 Access Seed/Key No N/A DF55 uint32 1 bit 0 to 4,294,967,292 When this PGN is transmitted, this field
contains a Seed that may be used in a
subsequent Unlock operation. This field is also
used to provide a Key to the PB200 when
performing an Unlock operation, using the
Command Group Function PGN 126208 (see
text below).
Notes
The Access Level proprietary PGN is a security mechanism that provides the PB200 with a method to limit access to certain functions to devices that understand the proper unlock
sequence. Certain operations will not be possible unless the Access Level is first increased to the required value. A nonzero Access Level remains in effect until the unit powers
down, or 15 minutes has elapsed, whichever comes first, after which the Access Level returns to zero. The Access Level is not stored in EEPROM.
This PGN is transmitted in response to a PGN 126208 Request Group Function message. Fields 1 and 3 must both be fully specified in the request in order for this PGN to be
transmitted.
Note that the value in field 4 (Format Code) may correspond to a specific set of algorithms for calculating the key from a given seed.
If field 4 is specified in a Request Group PGN 126208, but does not agree with the format code known by the device, then the request will be NAK'ed. If field 4 is not specified in
a request, then the PGN will be transmitted with the format code known to the device.