SRDF/S to SRDF/A

Ajay, it looks like the document that was referenced may be outdated. If you look on page 41 of the EMC SRDF Host Component for z/OS Product Guide. The link to the guide is http://powerlink.emc.com/km/live1/en_US/Offering_Technical/Technical_Documentation/300-007-862_a02.pdf

And here is an excerpt from that guide:

SRDF/S ¿ SRDF/A mode change

SRDF/S ¿ SRDF/A mode change functionality enables you to switch
between asynchronous mode and synchronous mode while
maintaining dependent write consistency on the remote R2 side
throughout the process. This functionality only applies to a single
SRDF/A group.

As an example, this feature could be used during processing where
transactions are so numerous that the application might not tolerate
the latency involved with handling the transaction load while in
synchronous mode. With the mode change capability, if you are
currently using SRDF/S, you can switch to SRDF/A mode during
high workload periods to minimize performance impacts to
applications. Once the overload situation has passed, you can switch
from SRDF/A back to SRDF/S mode (and catch up tracks owed)
before reverting to SRDF/A again if necessary.

To switch between SRDF/S and SRDF/A mode, use the SC SRDFA
command with the ACT or CONS_DEACT action. Use ACT to switch
to SRDF/A mode. Use CONS_DEACT to switch to SRDF/S mode.
Table 14, ¿#SC SRDFA command actions for SRDF/A mode,¿ on
page 317 provides more information on these actions.