User Manual

Table Of Contents
Safe Torque-Off (STO)
Advanced Digital Motor Controller User Manual 41
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
FIGURE 2-9. STO fault status LED pattern
2. STO Fault LED at Roborun+ utility in failure
FIGURE 2-10. STO fault position in Fault Flags
This failure can have several internal and external reasons. If the failure is shown please
check the cabling and the signals to STO 1 and STO 2. Both signals much have at all times
the same level.
Check that the STO jumper is set correctly and STO is configured correctly
Check wiring
Check cabling for short circuits or open circuits
If the failure persists, contact Roboteq support.
IMPORTANT WARNING
Same status LED pattern is used for undervoltage and overvoltage faults and that
should not be confusing. If STO fault appear it is normal for the controller voltage to
be off and undervoltage fault to trigger. Either way this Status LED pattern indicates
a situation that should be treated with caution.
Firmware implementation
The STO circuit will operate regardless of the MCU activity. However, when operating nor-
mally the MCU will perform the following functions:
1. Self-test that the STO circuits, switches and the power MOSFETs are functional.
This is done every time the controller is powered on. It can also be done at any time
using command STT (see STT - STO Self-Test, p.205) from the system’s PC or PLC.
The self-test can also be initiated by the controller itself using its scripting language,
at periodic time intervals, or any other user-define rule(s).
If the self-test fails, the controller will stop driving the MOSFETs and set a fault flag
that can be monitored by the PLC/Computer. It can also activate one of its digital
outputs to indicate the fault.