Siemens SINUMERIK Series Function Manual

N3: Software cams, position switching cycles - only 840D sl
8.4 Position-time cams
Extended Functions
552 Function Manual, 03/2013, 6FC5397-1BP40-3BA1
Properties of position-time cams
● The pulse duration is independent of the axis velocity and travel direction reversal.
● The pulse duration is independent of changes in the axis position (Preset).
● Activation (rising signal edge) takes place only when the cam position is crossed.
Moving the axis position (e.g. preset) does not trigger activation.
● A lead/delay time is operative for the minus cam and causes a time displacement of the
pulse.
● Activation (ON edge) and pulse duration are independent of the travel direction.
● The cam is not deactivated if the cam position is crossed again when the cam is active
(direction reversal).
● The cam time (pulse width) is not interrupted and the cam time not restarted when the
cam position is crossed again.
This behavior is particularly relevant with respect to modulo axes, i.e. if the cam time is
greater than the modulo range crossing time, the cam is not switched in every revolution.
Settings
The following settings must be made to program a position-time cam:
● Position
The position must be defined by a cam pair with which the minus cam position is equal to
the plus cam position.
This is defined using setting data:
SD41500 SW_CAM_MINUS_POS_TAB_1
...
SD41507 SW_CAM_PLUS_POS_TAB_4.
● Pulse duration
The pulse duration is calculated by adding together the associated entries for the cam
pair in:
MD10461 SW_CAM_PLUS_LEAD_TIME[n]
SD41521 SW_CAM_PLUS_TIME_TAB_1[n]...
SD41527 SW_CAM_PLUS_TIME_TAB_4[n]
● Offset
The time displacement of the position-time cam is calculated by adding together the
associated entries for the cam pair in:
MD10460 SW_CAM_MINUS_LEAD_TIME[n]
SD41520 SW_CAM_MINUS_TIME_TAB_1[n]...
SD41526 SW_CAM_MINUS_TIME_TAB_4[n]
● Mode
MD10485 SW_CAM_MODE
Bit 2 = 1 must be set in the machine data to ensure that all cam pairs with the same
values for minus cam and plus cam positions are treated as position-time cams.

Siemens SINUMERIK Series Specifications

General

Axes Control	Up to 31 axes
Category	Control Unit
Manufacturer	Siemens
Series	SINUMERIK
Control Type	CNC
Communication Interfaces	Ethernet, USB
Operating Temperature	0°C to 45°C
Protection Class	IP20
Power Supply	24V DC
Display	Color TFT LCD