Part-Revolution Clutched Machinery
A two-hand control safety module can be used for the following functions: “inch” (jog), “single-stroke,” or “continuous” (run). Two-hand
control safety modules are recognized as a means of protecting the machine operator when the hand controls are safely located and
protected from false operation (see
on page 9) and when properly
interfaced to the machine (see
on page 10) to control the required stopping action.
Full-Revolution Clutched Machinery
A two-hand control safety module used to initiate the cycle of a full-revolution clutched machine is known as a “two-hand trip device.”
Two-hand trip devices are recognized as a means of protecting the machine operator when the hand controls are safely located and
protected from false operation (see
on page 9) and when properly
interfaced to the machine (see
on page 10) to prevent accidental cycle initiation.
Theory of Operation
The input circuit of the DUO-TOUCH SG Safety Module requires simultaneous actuation (within 0.5 seconds of each other) of both two-
hand control actuators to generate an output signal.
The timing diagram illustrates that an output signal from the DUO-TOUCH SG Safety Module occurs only if switch #1 (SW1) and switch
#2 (SW2) are actuated within 0.5 seconds of each other. The output signal drops within 35 milliseconds following the release of either
switch. The device output does not re-energize until both hand controls are disengaged, and then simultaneously re-actuated. This logic
reduces the possibility of defeating the two-hand control by tying down one or both hand controls.
Power
SSI
M1
M2
ML
Feedback
Loop*
SW1
SW2
Output
< 0.5 s
< 0.5 s
> 0.5 s
Feedback
Open
SW1 (or SW2)
tied down
Mute
Cycle
Stop caused by
opening MI
SSI Stop
command
THC prevented
by open SSI
< 3.0 s
Figure 2. DUO-TOUCH SG Safety Module AT-xM-11KM timing diagram
* Feedback loop can remain closed at all times (if jumpered), when no monitoring contacts are available.
Muting M1 and M2 Inputs
“Muting” is the automatic suspension of the safeguarding function of a safety device during a non-hazardous portion of the machine
cycle.
To mute the two-hand control buttons appropriately, the muting system’s design must:
1. Identify the non-hazardous portion of the machine cycle,
2. Involve the selection of the proper muting devices, and
3. Include proper mounting and installation of those devices.
The M1 and M2 muting devices must have normally open contacts, or one device with a PNP output and one device with an NPN output.
Both devices must fulfill certain input requirements (see Muting Device Inputs in
on page 15). Several types of devices
may be used, including (but not limited to): limit switches, photoelectric sensors (opposed or polarized-retroreflective), positive-driven
safety switches, and inductive proximity sensors.
DUO-TOUCH
®
SG Two-Hand Control Modules
4
www.bannerengineering.com - tel: 763-544-3164
P/N 109782 Rev.B