Siemens SIMATIC FM 351 - Starting the Incremental Mode; Start Commands for the Incremental Mode

9
9-12
FM 351 Positioning Function Module
EWA 4NEB 720 6001-02
1I2; 2I2
Start, DIR_P,
DIR_M
POS
s
v
creep
v
rapid
WORKING
WAIT_EN
Figure 9-3 Starting the Incremental Mode
The methods of starting an incremental mode are dependent on:
 The type of incremental mode (relative or absolute).
 The type of axis.
The FM 351 evaluates the rising edge of the start signal. In this respect,
please take note of Chapter 9.9.
The FM 351 starts the positioning after detecting the start command and
when all start conditions are fulfilled.
You have the following possibilities for the start:
Table 9-5 Start Commands for the Incremental Mode
Type of Axis Start Command for
Relative Incremental Mode
Start Command for
Absolute Incremental Mode
Linear axis DIR_P; Start in positive direction
DIR_M; Start in negative direction
START: Start for the absolute target position.
The direction is unambiguously defined by the
target and the current actual value.
Rotary axis DIR_P; Start in positive direction
DIR_M; Start in negative direction
START: The target is approached along the
shortest path.
DIR_P: Start in positive direction.
DIR_M: Start in negative direction.
Starting
Sequence
Start Command
Operating Modes and Settings