Safety technology: MCB14x Document No.:
MG34Y104
Rev.: 06 23 October 2012 Page 11 of 25
4.3.
Safety outputs
The outputs (Ramp, STO_O, ExC and SSO) are safe positive switching semiconductor outputs and are only
enabled if all safety circuits (SKR-SS1, SKR-SLS and SKR-Door) are enabled.
All safety outputs are immediately destaged in the event of a fault or the forced opening of monitored protective
devices.
Ramp
Ramp is the control signal for the controlled slowdown of the drive. Each falling edge of this output causes the
frequency converter to trip a braking ramp and starts time monitoring activities at the same time. The drive is
expected to come to a standstill within this time frame.
The destaging of Ramp is tripped by enabling SS1 for the drive that is currently in motion.
If the drive is already at a standstill at the time SS1 is tripped, then the ramp start shall not be generated.
If no speed monitoring is implemented, then the drive shall always be deemed continuously in motion, and an
exclusively time-controlled braking ramp shall be tripped each time SS1 is pressed.
Ramp down time monitoring time
P 301
Disabling/enabling of speed detection
P 201
Table 8: Parameters for setting up the Ramp output
STO_O
Each time the STO_O output is destaged, this trips STO on the frequency converter (this signal must always be
connected to terminal 37 for Danfoss VLT frequency converters).
Once SS1 is enabled, such destaging always occurs if either the monitoring time has elapsed or the drive was
detected by the sensors as being at a standstill.
ExC
The ExC output is intended to directly control the energy isolator (contactor). Its switching behaviour is the same as
the STO_O output described above.
Use of energy isolator feedback contact
P 201
Table 9: Parameters for setting up the ExC output
SSO
The SSO output controls the enabling of the protective interlock in the event the drive is detected as being at a
standstill. This output is only enabled if speed detection is enabled and the drive is at a standstill.
Disabling/enabling of speed detection
P 201
Use of interlock feedback contact
P 105
Table 10: Parameters for setting up the SSO output
4.4. Pr_1/2
Sensor inputs for speed detection
Suitable initiators are required for speed detection purposes. When mounting them, efforts must be made to ensure
that an initiator always supplies 24 V for a dual channel measurement. This is necessary in order to ensure faults
can be detected.
The proximity switches cannot be supplied from the MCB 140. The 0 V common reference potential must be
connected.
Operation without any proximity switches is possible, and derates the MCB 140 to a safety module for time-
monitored brake function and subsequent STO operation.
Figure 3: Mounting of proximity switches
2 or 3-wire proximity switches may be used (2-wire may only be used with 24 V supply)
Number of sensors used
P 201
Use of 2/3-wire initiators
P 202
Permitted start-up delay following Start/Stop enabling
P204
Table 11: Parameters for setting up the Pr_1/2 inputs
1
3
0
B
D
8
5
7
.1
0
Input signal pattern at a standstill when in motion
Senso
r
Sen
sor
Pr_1
Pr_2
Gear wheel
Gear
