Output; Permitted Sensor Types On Digital Inputs; Reset; Signal Filtering - Danfoss VLT MCB 150 Operating Instructions Manual

Functions and System Overvi...

3.6.3 Output

Safe, single-pole output
S37 is the output that goes to the Safe Torque Off input of
the frequency converter.
3 3
•
Safe Torque Off Acknowledge
-
-
-
-
-
3.6.4 Permitted Sensor Types on Digital
Inputs
The following sensor types are applicable
•
sensors with 2 NC contacts
•
antivalent contacts (1 NO contact and 1 NC
contact)
•
sensor output of type 2xPNP
Sensors with 2 NO contacts are not applicable.
The safe digital inputs are configured for both directly
connecting safety sensors, e.g. emergency stop control
devices or light curtains, as well as for connecting pre-
processing safety relays, e.g. safe controls. See examples of
connecting the safe digital input, in accordance with EN
ISO 13849-1 and EN IEC 62061 in chapter 4.3.1 Connecting
Safe Digital Inputs.

3.6.5 Reset

CAUTION
Both safety inputs must be off after an input fault or
PUST has occurred, before a reset is accepted to branch
into safe monitoring again.
This reset must only be possible at the location where
the safety command has been initiated.
To operate the safety option, the application must send a
reset signal either via the LCP, via a dedicated digital input
or via a control word. When a safety function has been
activated, or an external failure has caused a failure state, a
reset is necessary to enable the safety option again. When
the connected sensor on DI1 or DI2, or both is enabled via
a reset, the safety option can be switched on again. This
deactivates active safety functions or errors.
22
Operating Instructions
Internal error on frequency converter or
safety option
Limit values exceeded
Activated via SS1
PUST (Power Up Self Test)
External failure
Danfoss A/S © Rev. 2014-02-11 All rights reserved.
NOTICE
First, trip alarms displayed on the frequency converter
must be acknowledged after which a pending safety
function can be acknowledged. A single reset for the
alarm mode and a second reset for acknowledgment of
the active safety function. Alarms caused by the
frequency converter must be reset before an alarm can
be reset on the safety option.

3.6.6 Signal Filtering

If a sensor with 2NC or 1NC/NO is selected, the safety
option checks the signals of the safe digital input for
consistency. Consistent signals at both inputs always
assume the same signal state (high or low). If 1NC/1NO is
selected, it checks the right state of each input.
With electromechanical sensors (e.g. emergency stop
buttons or door switches), the 2 sensor contacts never
switch at the same time (discrepancy). A long-term
discrepancy points towards a fault in the wiring of a safe
input, for example, a wire break. An adjustable filter in the
safety option prevents faults caused by temporary or short-
term discrepancy. Within the filter tolerance time
42-22 Discrepancy Time, the safety option suppresses the
discrepancy monitoring of the safe inputs.
Input Signal
DI1/DI2
D1 x A
D1 x B
Discrepancy time
Safety function
Active
Inactive
Illustration 3.14 Discrepancy Time
Parameterise the discrepancy time of the switching
elements connected to the digital inputs. The default value
is 10 ms.
MG34W302