SIERRA VIDEO SYSTEMS Tahoe 2010A, User Manual

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Sierra Video Systems
30
“B”: Output Lock inquiry or change
The command "
B
" requests that lock information for the specified output be returned to
the host, and optionally that the lock status of that output be changed. Whenever the
router receives a “B” command, it sends one back.
In routers that support the “B” command, the router reports changes to output lock status
using the “B” command, not the “G OUTPUT_LOCK” command.
When an output is locked, it cannot be routed to a new input unless the password sent
using the “K” command matches the password used to lock the output.
In virtual-mapped routers, this command applies lockouts to
virtual destinations
rather
than
physical outputs
, so the word “output” should be replaced with “destination” in this
command description.
If the “password” and “lock” arguments are both 0, this is a query for lock status of the
specified output. A “B” command is sent to report the lock status.
If the “password” argument is not 0, this is a request to change the lock status of the
specified output. After changing the lock status, a “B” command is sent to report the new
lock status, so a response occurs regardless of which form of the “B” command is sent to
the router.
When requesting that lock status be changed, if “lock” is 0, this is a request to unlock the
output, and if “lock” is 1, this is a request to lock the output. An attempt to lock an output
that is already locked, or to unlock an output that is already unlocked, fails, as does an
attempt to unlock an output using a password that is different from the password that the
output was locked with and is not the administrator password. Any use of a password
larger than 9999 also fails. In any of those cases, the output lock status remains
unchanged and an error response is generated. The “B” command response will indicate
that the output still has the same lock state as before.
In the “B” command response that is sent by the router, the “password” argument is the
current lock password for the output (1-9999), or is 0 if the output is not locked, and the
“lock” argument is 0 if the output is not locked, or 1 if it is locked.
When locking an unlocked output, the specified password is recorded by the router as the
lock password for that output. When unlocking a locked output, the specified password is
compared by the router to the lock password for the output. If they match, or if the
specified password is the administrator password, the output is unlocked, else it remains
locked. Attempting to lock an already-locked output, or unlock an already-unlocked
output, has no effect on the lock state of that output.
Whenever a
take
is done, the router checks to see if the specified output for the
take
has
been locked. If so, the current password of the control port that sent the
take
request (as
set with the “K” command) is compared to the output’s lock password. If they match, the
take
is allowed, but if not, the
take
has no effect. The
administrator password may NOT
be used in lieu of the output’s lock password to do a take,
so if a controlling device sends
the administrator password in a “K” command, that will not permit the device to reroute
locked outputs (but it can use the administrator password to unlock locked outputs using
the “B” command).
Output lockouts apply on
all levels.
On virtual-mapped routers, a level may be left out of a
lockout by making sure the level is unmapped for the destination being locked.
As with all router configuration parameters, the output lockout data is stored in non-
volatile storage and thus is retained across router power-ups. When a router is first
initialized at the factory, all outputs are set to be unlocked.
This command provides the same functionality as the “G OUTPUT_LOCK” command.
This command, which was added at router software version V5.06, is preferred over that
command. Note that the output lock version number is not present in this command.