Envoy ACP/XF Application Programming Manual

Normal Response Mode (NRM) Protocols
EnvoyACP/XF Application Programming Manual–132179
3-28
Shutting Down a Data Link
If the secondary station issues CONTROL 18,1, the station remains in the Information
Transfer State (ITS) and responds with RD to any further messages (other than a DISC)
from the primary station (Figure 3-7). The primary station either responds with a DISC
command or ignores the RD request.
Figure 3-6. Secondary Station Issues CONTROL 18,0
Note. If a primary station sends a SNRM to a secondary station, the secondary station
responds with a UA unless an error occurs or the secondary station is in disconnected mode.
Figure 3-7. Secondary Station Issues CONTROL 18,1
046
Secondary Station
Primary Station
User Issues
CONTROL 18
or
CONTROL
18,0
Station
goes into
Logical Disconnect
State (LDS).
RR, P
DM
047
Secondary StationPrimary Station
User Issues
CONTROL 18,1
Station
remains in
Information
Transfer State
(ITS).
RD
any message, P
DISC
UA