Processing

DMTSNE uses two RPLs to communicate with VTAM. It uses the first to issue SEND macros when filled buffers can be sent on the link. DMTSNE uses the second RPL to issue RECEIVE macros when it must receive buffers from a remote node.

When it uses the SEND RPL, DMTSNE also uses two wait lists. The first wait list checks for files and messages to send to the remote node. It may also check for link driver commands and the completion of the RECEIVE RPL. If data is available to send, DMTSNE calls DMTNTR to fill the buffers.

DMTSNE uses the second wait list when all the send buffers are filled. It waits for VTAM to accept the buffer by posting the completion ECB for the SEND RPL. DMTSNE then calls DMTNTR to fill the buffer with more data.