5 system resets and lockout conditions, 6 reset signal requirements, 73 and – Banner SC22-3E Safety Controller with Ethernet User Manual
Page 74
7.5 System Resets and Lockout Conditions
A system reset is necessary under the following conditions:
• Recovering from a lockout condition
• Starting the Controller after a new configuration has been downloaded
• Recovering from an output fault
• Entering Run mode after power-up, when configured for manual power-up
• Exiting Enable mode
• Recovering from an AVM fault
• Recovering from a two-hand control input fault
A system reset is used to clear lockout conditions not related to safety inputs. A lockout condition is a response where the Controller will
turn OFF all affected Safety Outputs when a safety-critical fault is detected. Recovery from this condition requires all faults to be rem-
edied and a system reset to be performed. A lockout will recur after a system reset unless the fault that caused the lockout has been
corrected.
The reset device (a button or switch) connects to a dedicated input terminal on the Safety Controller, labeled SR. The reset signal type
can be configured to be either monitored or non-monitored (the default setting is monitored); see section
on page 34.
WARNING: . . . Non-Monitored Resets
If a non-monitored reset (either latch or system reset) is configured and if all other conditions for a reset are in place, a
short from the Reset terminal to +24V will turn ON the Safety Output(s) immediately.
WARNING: . . . Check Before Reset
When performing the system reset operation, it is the user’s responsibility to make sure that all potential hazards are
clear and free of people and unwanted materials (such as tools) that could be exposed to the hazard. Failure to do so
could result in serious bodily injury or death.
7.6 Reset Signal Requirements
Both manual (latch) reset and system reset signals can be configured for monitored or non-monitored operation, as follows:
Monitored resets—Requires the reset signal to transition from low (0V dc) to high (24V dc) and then back to low. The high state duration
must be 0.3 to 2 seconds. This is said to be a “trailing edge trip event.”
Non-monitored resets—Requires only that the reset signal transitions from low (0V dc) to high (24V dc) and stays high for at least 0.3
seconds. After the reset, the reset signal can be either high or low. This is said to be a “leading-edge trip event.”
SC22-3/-3E Safety Controller Instruction Manual
74
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