GRYPHON
®
- S3 MANUAL
© 2006
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front panel, or the "Time and Date" fields in the "System Administration" web page of the Gryphon, or
the "date" command in a telnet session.
A Gryphon timestamp is embedded in every FT_DATA frame routed to a client. The timestamp value
indicates the relative time when the encapsulated payload frame (e.g., CAN bus frame) was received
and processed by the channel's device driver. It is a 32-bit unsigned integer, representing a time
interval in units of 0.00001 seconds (10 micro-seconds).
The Gryphon timestamp is derived directly from the Gryphon time -- it is the lower 32-bits of the latter.
5.4 Channel speed
The bit transmission rate and other physical layer timing characteristics of a channel may be
controlled by the user in two ways: through the use of "preset speeds", and through the use of IOCTL
commands and data values specific to the channel hardware type.
1.4.1 Preset speeds
Some bus protocols are specified as having a fixed number of standard bit rates. For example, GM's
"Class 2" implementation of SAE J1850 is defined as having two: "normal mode" at 10.4 kbps and
"4X mode" at 41.6 kbps. To facilitate the user control of channel bit rates, the Gryphon is built with a
set of "Preset Speeds" for the different channel types. Thus, for the "GM J1850 / DLC module"
channel type, there are two preset speeds: the first corresponds to "normal mode", and the second
corresponds to "4X mode".
1.4.2 Arbitrary speeds
Some bus protocols are defined to operate over a wide range of bit rates, and other bit timing
characteristics. For the channel types supporting these protocols, the user may need to use the
IOCTL method to get complete control over bus timing characteristics.
As a convenience, however, these channel types may also have "preset speeds" defined, especially
for the more commonly used bit timing settings.
5.5 Message filtering
Clients use message filtering to control the routing of FT_DATA frames from a channel to a client.
When a client begins a session with the Gryphon server the filter mode for all channels, with respect
to that client, is "FILTER_OFF_BLOCK_ALL". In this mode, no bus traffic will be routed to the client.
If the client sets the filter mode of a channel to "FILTER_OFF_PASS_ALL", then all bus traffic
received by that channel will be routed to the client.
Finally, if the client sets the filter mode of a channel to "FILTER_ON", then only those received bus
frames that are passed by an active filter, or by the default filter action (described below), will be
routed to the client.
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