Siemens SINUMERIK 828D Function Manual page 531

REPOS acknowledgement operations
With the channel-specific VDI signal:
DB21, ... DBX319.0 (REPOSMODEEDGEACKN)
if a "handshake" is established by the interface signal:
DB21, ... DBX31.4 (REPOSMODEEDGE)
recognized by the NC and acknowledged with DB21, ... DBX319.0 to the PLC.
Note
If the NCK has not yet acknowledged interface signal:
DB21, ... DBX31.4 (REPOSMODEEDGE)
with interface signal:
DB21, ... DBX319.0 (REPOSMODEEDGEACKN)
a RESET in this situation causes the program to abort, and the REPOS that is to be used to
control the REPOSPATHMODE can no longer take place.
A REPOSMODE specified by the PLC from NCK with the interface signals:
DB21, ... DBX319.1-319.3 (Repos Path Mode Ackn0 to 2)
and
DB31, ... DBX10.0 (Repos Delay)
with:
DB31, ... DBX70.2 (Repos Delay Ackn)
in the following way:
A part program is stopped at N20 ( → time (2) in figure). The NCK stops according to the braking ramp. After the
PLC has specified the REPOSPATHMODE, the NCK accepts the REPOSPATHMODE with the 0/1 edge of
REPOSMODEEDGE at → Time (3). Repos Path Mode Ackn remains set until the ASUB is initiated ( →
Time (4)). The REPOS command is started in the ASUB ( → Time (5)). The ASUB RESET block is activated
again ( → Time (6)):
Basic Functions
Function Manual, 09/2011, 6FC5397-0BP40-2BA0
K1: Mode group, channel, program operation, reset response
9.8 Block search Type 5 SERUPRO
531