Single Setting Do Not Evaluate Enable Input; Behavior Of The Start Signals During The Operating Modes - Siemens SIMATIC FM 351 Installation Manual

9.9

Single Setting Do Not Evaluate Enable Input

Definition
The start of an operating mode for a channel is normally only possible, if the
appropriate enable input is set:
You therefore have the possibility of preparing an operating mode for start-
ing. The actual start is then independent of the program sequence in the your
user program. You start the operating mode by applying a "1" on the enable
input.
Switching the When you switch off the evaluation of the enable input, an operating mode
Evaluation Off starts immediately after detection of the start signal. It is then not possible to
prepare an operating mode and to start it at a defined later point in time.
Start Enable in The operating modes are started differently in the FM 351. You must differ-
Dependence of the
entiate between:
Start Signal
Table 9-9 shows you the start signals for the various operating modes:
Table 9-9
Jog
Seek-reference-point
Absolute increment
Relative increment
Requirements for
In order that an operating mode actually starts, the following requirements
Starting an must be fulfilled:
Operating Mode
FM 351 Positioning Function Module
EWA 4NEB 720 6001-02
Digital input 1I2 for Channel 1
Digital input 2I2 for Channel 2
Edge-controlled start signals.
Level-controlled start signals.

Behavior of the Start Signals during the Operating Modes

Operating Mode Start Signal is
Level-Controlled
DIR_P, DIR_M
The operating mode has been prepared with a set start command using an
FC.
The enable input must be switched on.
Operating Modes and Settings
Start Signal is
Edge-Controlled
START, DIR_P, DIR_M
START, DIR_P, DIR_M
DIR_P, DIR_M
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