User Manual

Safety Recommendations
40 Advanced Digital Motor Controller User Manual V2.0, July 8, 2019
Safe Torque Off (STO) on Roboteq Controllers
Two digital inputs on the user IO connector can be used to put the controller in a state
where the motor is deprived of energy.
The two inputs, labeled STO1 and STO2 must both be brought and maintained at a logic
level 1 for the controller to be active. If any one or both of these lines are at 0, the output
is de-energized.
The STO circuit operates independently of the MCU. It will always override the MCU,
whether the MCU is processing normally, or is in a hardware of firmware fault condition.
The STO circuit works by controlling the voltage supply to the controller’s MOSFET driv-
ers. When both STO1 and STO2 are at logic 1 level, the MOSFET driver are supplied with
power. When either or both STO1 and STO2 are at logic level 0, the MOSFET driver power
is cut, and the MOFETs gates can no longer be above the ON threshold level, regardless
of the MCU activity.
Accordingly, the STO circuit is built with redundancy and will continue to function if any
one component is faulty, anywhere in the STO circuit or elsewhere in the controller.
Activating STO
By factory default STO is disabled. It must be enabled by removing the jumper located on
the controller’s PCB. STO is activated by removing power (logic level 0) to both STO in-
puts. In order for controller to monitor STO state, this function must be activated through
Roborun+ Utility or serial command (check command section). The controller will imme-
diately stop generation of torque in the motor. STO functionality is only available in the T
version of the controller.
Deactivating STO
STO is deactivated by applying a voltage (logic level 1) to both STO inputs. After this a new
start command has to be given to turn the motor. It can be disabled by connecting the
jumper located on the controller’s PCB. After that user should disable the function through
Roborun+ Utility or serial command (check command section).
Constraints when using STO
• The STO feature is only approved for use with Brushless DC or AC Induction motors.
• All voltages attached to the controller need to fulfil SELV or PELV requirements.
• After first installation and at least every 3 months the test as described in chapter
14 has to be conducted.
Sto Failure Messages
In case a failure is detected in the STO circuit the following failure message will be visible
according on how the user operates the controller.
1. Status LED on Controller
The status LED pattern will be the below in case of STO failure