Technical Details; Response Times; Input Voltage Levels; External Dark Test Pulse Filtering Capability - Vacon optbj Safety Manual

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5.3

Technical details

5.3.1

Response times

5.3.2

Input voltage levels

STO inputs fulfill the requirements for standard operating ranges for Type 2 digital inputs (current
sinking), defined by IEC 61131-2 (2007). Reversed polarity applied on STO input terminals does not
cause disabling of STO function.
The STO inputs of OPTBJ are OSSD tolerant. The operation of OPTBJ is not interfered by test pulses
that are generated to the STO lines by the connected safety actuator as long as the test pulses fulfill
certain requirements. See chapters 5.3.3 and 5.3.4 for details.
Technical item or function
Input Voltage (logic 1)
Input Voltage (logic 0)
Input Current (logic 1)
Input Current (logic 0)
Input Resistance
Galvanic Isolation
Short circuit protected
Active -> Inactive Debounce time
Allowed discrepancy time of physical inputs
5.3.3

External dark test pulse filtering capability

To recognize the short circuits from STO lines to power supplies or ground, some safety PLCs test
their outputs by pulsing the output from high to low level for short periods of time when STO is dis-
abled. The pulses are known as 'dark test pulses'. To prevent these test pulses from causing false
fault indications, these dark test pulses are filtered out by STO inputs on OPTBJ. If the input voltage-
specific values for dark test pulse durations are exceeded, the drive may indicate STO diagnostics
fault or STO may be activated. The used dark test pulse duration should always be shorter than the
specified minimum pulse withstanding duration. Limits for the test pulse duration, frequency and
period are given in Table 5. The filtering time is hardware-based and cannot be adjusted. External
dark test pulse filtering is included on OPTBJ boards from revision D onwards. See chapter 4.1 for
identifying the board revision.
Dark test pulse filtering capability
STO input voltage: 11 V
STO input voltage: 24 V
STO input voltage: 30 V
5
Table 2. STO response times
Safety function
Safe Torque Off (STO)
Table 3. Safe input data
Table 4. External dark test pulse filtering capability
Activation
activation
time
< 20 ms 500 ms
Minimum Typical
11 V 24 V
-3 V
4.5 mA 7.5 mA
2.5 kΩ
4 ms
Minimum Typical
0 ms 0 ms
4 ms 4 ms
5 ms 6 ms
Local contacts: https://www.danfoss.com/en/contact-us/contacts-list/
STO and SS1 safety functions
De-
time
Maximum
30 V
0 V 5 V
8 mA
2.0 mA
Yes
Yes
9 ms
500 ms
Maximum
1 ms
7 ms
9 ms