Banner SC22-3E Safety Controller with Ethernet - Manual (Page 36)

4.6.2 Two-Hand Control (THC)
The two-hand control function requires that two hand actuators (e.g., hand/palm buttons) each be activated within 0.5 seconds of each
other in order to produce a Run signal to start a machine cycle. THC devices are always the last input (in time) to turn the Safety Output
ON. If one or more of the other controlling input devices are configured for manual reset and are used to stop the machine, a manual
reset must be performed before the THC device can cycle the machine again.
See section 10.5 Two-Hand Control on page 100 for more information.
Two-Hand
Control Device
Safety Device 2
(Manual Reset)
Reset Signal
Safety Output
Figure 17. Timing logic: two-hand control device and manual reset safety input device
Two-Hand Control Activation on Power-Up Protection. The Controller’s two-hand control logic will not permit the assigned Safety
Output to turn ON when power is initially supplied while the THC actuators are in their Run state. The THC actuators must change to their
Stop state and return to the Run state before the Safety Output can turn ON.
A two-hand control device does not have a manual reset option.
4.6.3 Enabling Devices
The enabling device actively controls the suspension of a Stop signal during a portion of a machine operation where a hazard can occur.
The enabling device permits a hazardous portion of the machine to run, but must not start it. A separate machine command signal from
another device is needed to start hazardous motion. This enabling device must have ultimate hazard turn OFF or Stop authority
when being used. The enabling device is sometimes referred to as the “live man pendant.”
An enabling device can be mapped to one or more Safety Outputs. When the enable signal goes from the Stop state to the Run state, the
Controller will go into Enable mode. In this mode, the associated Safety Outputs will turn ON if any of the assigned EDM inputs are
closed (these may open after the outputs turn ON) and all of the controlling E-stop or rope pull devices are in their Run state. With the
exception of the E-stop and rope pull devices, all other safety input signals (Run or Stop) will be ignored while the Controller is in Enable
mode. Safety Output enabling control resides in the enabling device function when in Enable mode. Repetitive enable cycles are allowed.
In order to exit Enable mode, the enabling device must be in the OFF state, and a system reset must be performed.
Enabling Device Time Limit. The enabling device time limit can be adjusted between 1 second and 30 minutes and cannot be disabled.
When the time limit expires, the associated Safety Outputs will turn OFF. In order to start a new Enable mode cycle with the time limit
reset set to its original time limit value, the enabling device must switch from ON to OFF, and back to ON.
All ON- and OFF-delay times associated with the Safety Outputs that are controlled by the enabling device function will be honored
during the Enable mode.
SC22-3/-3E Safety Controller Instruction Manual
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