Accelnet Plus Micro Modules User Guide
16-01687 Rev 03
Copley Controls
Page 100 of 139
P
ERIODIC
STO
T
ESTING
I
NTERVAL
To meet SIL 3 and/or Cat. 3 PL e performance of the Safety Function, periodic diagnostic
testing is required to be performed every 3 months, per IEC 61800-5-2. The AEV and APV
drives have internal diagnostics testing software to verify the function of the STO circuits
every 24 hours. If a fault is detected, the AEV/APV drive shall be put into a Safe State until
the fault is cleared. This internal diagnostics testing software of the AEV/APV products fulfills
this requirement without intervention of the operator.
I
NTERNAL
D
IAGNOSTICS
P
ULSES
The AEV and APV drives have internal diagnostics to verify the function of the STO circuits.
The diagnostics test sends short (60 microseconds) pulses that propagate through the STO
circuits and monitors a response to verify hardware integrity of each channel without
interfering with drive operation. When both STO1 and STO2 inputs are energized the
diagnostics test runs within 20 milliseconds. If the diagnostics test passes, the diagnostics
test shall run every 24 hours as STO1 and STO2 remain energized. If the STO diagnostic test
detects a failure, then the drive shall be put into a safe state and the test shall be run every
5 seconds until the test passes on STO1 and STO2 input channels. The following figure is
intended as a visualization of the internal diagnostics testing.