Function Description For Digital Inputs - Siemens SIMATIC FM 353 Manual

Description of Functions
9.8.1

Function description for digital inputs

External start
The control signals of the axis include the start signal which triggers a positioning
operation in "Reference point approach", "MDI" and "Automatic" modes. A logical
OR is established with the "External Start" digital input and the control signal (ST).
External start is connected to digital input I1.
Example
ST
Digital "External start" input
Input I1 not inverted (MD36)
1
2
3
Minimum signal length at the digital input: w 2
Enable input
Setting the enable input is a prerequisite for positioning, movement or output of an
axis, if this is parameterized with MD34. A reset stops the movement (external
movement enable).
S In the Jogging and Control modes, the movement of the axis proceeds as long
as the AND link continues between the control signal (R+/R−) and the enable
input.
Example
R+ or R−
Enable
1
2
3
S In the other modes, note the following:
If the enable input is not yet set after a Start edge, this Start edge is stored in-
ternally and "Waiting for enable" is additionally displayed in the checkback sig-
nals. When the input is set, movement begins and the stored Start edge is de-
leted (a Stop likewise deletes the stored Start edge).
9-78
1
3
w1
2
1
3
&
Positioning
2
Control signal (Start)
Input I1 inverted (MD36)
@
FM cycle
FM 353 Stepper Drive Positioning Module
6ES7 353-1AH01-8BG0