Release 7/2009 Ver. 1.0
Technical Manual: GS-120 Light Curtain Systems
TAPESWITCH CORPORATION
Phone: 631-630-0442
100 Schmitt Boulevard
57
Fax: 631-630-0454
Farmingdale, New York 11735
www.tapeswitch.com
APPENDIX C – SRUB INTERFACE UNIT
1.0
GENERAL DESCRIPTION
The SRUB interface unit is designed to be incorporated
into the user’s machine control system. It interfaces a
GS-120 light curtain with the protected machine’s
controls. The SRUB requires a +24 Vdc input, which
must be common with the +24 Vdc. supplied to the light
curtain.
2.0
OPERATIONAL SEQUENCE AND LED
STATUS DESCRIPTION
Note:
The LEDs on the SRUB provide status indication
of the output state of the safety relays only. No status
indicators for the light curtain (emitter and receiver) are
provided on this unit.
2.1
RESETTING OPTIONS
The SRUB interface can be configured for either a
manual (latched) reset or and automatic reset. In the
manual reset mode, the safety outputs will go to the “off”
state (opened) once the light curtain is obstructed and
remain
in the “off” state until the obstruction is removed
and
an external (user supplied) reset switch is activated.
Once this reset sequence is completed, the safety
outputs will resume the “on” state (closed). In the
automatic reset mode, the safety outputs will follow the
state of the light curtain (i.e., light curtain clear: outputs
“on” (closed), light curtain obstructed: outputs “off”
(opened). The operational sequence for both reset
options is described below.
2.1.1
Manual Reset
When power is first applied to a light curtain system in
manual reset mode:
•
No LEDs will be illuminated until a manual (external)
reset is applied.
•
Once the external reset is applied, the two green
LEDs (channel 1 and channel 2) will illuminate.
(Provided the system is properly wired, no faults exist
and the GS-120 emitter and receiver units have power
and are properly aligned.) This indicates that both
safety relay outputs are in the “on” or closed state. Both
LEDs must be illuminated in order for the guarded
machine to operate.
•
These outputs will remain “on” (closed) until the light
curtain is obstructed, faulty or misaligned. If an
obstruction occurs, both green LEDs will go off and
remain off. The LEDs will remain off, even if the light
curtain is cleared, until a reset is applied.
•
Once a reset is applied the two LEDs will illuminate,
and the safety output relays will return to the “on”
(closed) state.
2.1.2
Automatic Reset
When power is first applied to a light curtain system in
automatic reset mode:
• Both green LEDs will illuminate and the safety output
relays will be “on” (closed). The LEDs and outputs will
remain on, provided the light curtain is clear.
• When the light curtain is obstructed, both LEDs will go
off and the safety outputs contacts will also go to the
“off” (open) state. They will remain off until the light
curtain is clear.
• Once the obstruction is removed, both LEDs will
illuminate and both safety output relays will return to the
“on” state.
• If one of the output signals from the GS-120 light
curtain is disconnected, the corresponding LED
(channel 1 or channel 2) will go off. Both safety output
relays will also go off and remain off. The system will not
reset, even if the signal is restored. This condition is
considered a catastrophic failure and requires a power-
down/power-up cycle to restore normal operation
(provided this failure has been rectified).
3.0
MECHANICAL INFORMATION
Figure 59
shows the case size and mounting
dimensions of the SRUB interface unit. All dimensions
are in millimeters. The unit must be mounted in an
enclosure rated for the known operating environment.
In most cases, the unit will fit into an existing machine’s
control unit panel. The unit snaps into a common
electrical mounting rail, style DIN EN 50 022-35.
