User's Manual

To lock a port, send an update to the port with the character “O” indicating that you wish to lock
the port for example:
SERIAL PORT LOCKS:
↵
7 O
↵
↵
ACK
↵
↵
SERIAL PORT LOCKS:
↵
7 O
↵
↵
To forcibly unlock a port that has been locked by another client, send an update to the port with
the character “F” instead of using the usual unlock character “U”. For example, to override a
lock on port 7:
SERIAL PORT LOCKS:
↵
7 F
↵
↵
ACK
↵
↵
SERIAL PORT LOCKS:
↵
7 U
↵
↵
Hardware status blocks can only be sent by the Videohub Server. If a client sends hardware
status blocks, they will be ignored.
Requesting a Status Dump
The client may request that the Videohub Server resend the complete state of any status block
by sending the header of the block, followed by a blank line. In the following example, the client
requests the Videohub Server resend the output labels:
OUTPUT LABELS:
↵
↵
ACK
↵
↵
OUTPUT LABELS:
↵
0 output label 1
↵
1 output label 2
↵
2 output label 3
↵
…
↵
Checking the Connection
While the connection to the Videohub Server is established, a client may send a special
no-operation command to check that the Videohub Server is still responding:
PING:
↵
↵
If the Videohub Server is responding, it will respond with an ACK message as for any other
recognized command.
921Developer Information