Control Function With Light Curtain; Mode Selector; Modes For Clock Operation; Starting The Press In Clock Mode - Siemens Simotion TM 121C Applications Manual

Control elements

4.5 Control function with light curtain

4.5.1

Mode selector

The mode selector (single stroke and two-stroke) is connected to simple digital
inputs. A short circuit between these signals is identified by means of the "1 of 2"
selection. An intermediate position is not required.
Comment
The light curtain receives its voltage supply from the Safety Unit through output
X2.x. Therefore, the light curtain is without voltage when the mode selector is set
to "Off".
Note
If the light curtain is not active, the power supply for the light curtain must be
switched off so that the unlit LED will indicate to the operator that the light curtain
is not operational.
4.5.2

Modes for clock operation

Definition
There are two modes for clock operation – the standard mode and the Sweden
mode. The only difference between the two modes is in the manner in which they
start after a restart inhibit.
Standard mode
In the standard mode, an interruption of the light field is initially required before
starting the machine or before starting it after a restart inhibit. After that, the first
start of the press must be initiated by the command device. The two-hand switch is
provided for this purpose.
Sweden mode
In the Sweden mode, a command device acknowledgement is required before
starting the machine or before starting it after a restart inhibit. The press is then
started by interrupting the light field (interrupting it twice in the case of the two-
stroke mode).
4.5.3

Starting the press in clock mode

In clock mode, the press is started after one or two interruptions of the light field.
The following conditions apply for these interruptions:
•
The prerequisites for the first start must be met.
•
The interruption must last longer than 100 ms.
•
The interruption must take place at the top dead center.
•
The previous interruption may not lie farther back than 30 s.
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© Siemens AG 2003 All Rights Reserved
SIMOTION Safety Unit (AP) - Edition 06.2003