Exchange/SNA Manual

Using Exchange/SNA in a Single-LU Configuration
Using Exchange/SNA in LU Configurations
G–2 104700 Tandem Computers Incorporated
contained the BDS also began a bracket (BB is set on in the RH), the BDS request is
rejected with sense data %H0813, Bracket Bid Reject. If the BIU did not begin a
bracket, the BDS request is rejected with sense data %H0825 (component not
available).
When a BDS is rejected, the host does not immediately send the BDS again. If the BDS
was rejected with sense data %h0813, the subdevice (on the host) enters the inactive
state. If the BDS was rejected with sense data %0825, the subdevice enters the drained
state. In both cases a console command to start the subdevice causes the host to send
the BDS again. For example, if the BDS specified printer one (PR1), the console
command $S R15.PR1 causes the BDS to be sent again (assuming you have logged on
as remote 15). If the subdevice is still not open, the BDS will be rejected again.
Therefore, you should issue a RECEIVE command for the subdevice (or the
application program should open the subdevice) before issuing the console command.
Instructions for Using a Single-LU Configuration
The most common situation in which a BDS is rejected is when the host has a job
queued for printing before the connection is established between Exchange/SNA and
the host. In this case, the host sends the BDS immediately after the LU-LU session is
established and the console message confirming the logon has been sent. This usually
happens so quickly that the BDS arrives and is rejected before the subdevice can be
opened. If you expect to encounter this situation, the following sequence of
commands will establish the connection and receive the queued job.
1. Issue a CONNECT command to establish the connection with the host.
2. Issue a RECEIVE command for the subdevice on which the job is queued. For
example, RECEIVE MYFILE:#PR1.
3. Issue a console command to start the subdevice. For example, $S R15.PR1.
4. The host will send the BDS again. Exchange/SNA will send a positive response to
the host because the subdevice is now open, and the job will be transmitted.