Siemens SIMATIC S7-300 Manual page 210

Description of Functions
Table 9-8 Control actions for "Automatic" mode (examples), continued
Signal name
Control action 10, delete start signal and residual path (special situation)
Control signal:
Start [ST]
Transfer "delete residual
path" (job no. 11)
Control action 11, positioning for rotary axis (special situation)
Control signals:
Direction plus [R+] or
direction minus [R–]
Start [ST]
Control action 12, deactivate operating mode during program execution (special situation)
Control signal:
Mode [BA]
Checkback signals:
Old mode [BAR]
Travel plus [FR+] or
Travel minus [FR–]
Processing in progress [BL]
New mode [BAR]
9.2.7 Automatic single block
Overview Functions, same as "Automatic" mode
Whereas in "Automatic" mode the FM 354 automatically starts processing
the next block after completing a given block, in "Automatic single-block"
mode the axis waits for a new Start signal after processing each block that
contains a traversing path, dwell time or M command (except for blocks with
G50, G88 or G89).
You can change between Automatic single-block and Automatic mode at any
time, without stopping the movement or interrupting the output.
9-34
Level
If "delete residual path" is also preselected on [ST], the block
interrupted by Stop is not executed up to the end, but the next
block is started immediately.
If the axis is operated as a rotary axis, the FM always at-
tempts to select the shortest path during positioning. This
direction preference can be suppressed by specifying [R+] or
[R–].
If a new operating mode is selected during active program
execution, the axis is stopped by way of the deceleration
ramp.
[FR+] or [FR–] and [BL] are reset.
Explanation
FM 354 Servo Drive Positioning Module