Configuration / project engineering
9.3 Explanation of the device's functions
3TK2826 safety relay
30
Manual, 08/2007, GWA NEB 926 1579-02 DS 02
9.3
Explanation of the device's functions
Explanation of the device's functions (DIP switches)
Table 9-3
Explanation of the device's functions
DIP
switch
Parameter
Function
1
Cross-circuit
detection
Cross-circuit detection is only possible with floating sensors. The sensors must be connected
between T1 - Y12, Y33 and T2 – Y22, Y34. The device expects the test signal of terminal T1 at
the terminals Y12 and Y33, and the test signal of T2 at the terminals Y22 and Y34. The device
detects a sensor fault if the signal at the terminals Y12, Y33 or Y22, Y34 does not agree with
the test signals T1, T2.
Cross-circuit detection must be deactivated if electronic sensors such as light arrays or laser
scanners are connected. The 3TK2826 now no longer monitors the sensor inputs for cross-
circuit detection. Uusually, the outputs of safety sensors (OSSD) are already monitored for
cross-circuits in the sensor itself.
If "without cross-circuit detection" is set on the device, the test outputs T1, T2 are deactivated
and may no longer be connected. At the inputs Y12, Y22, Y33 and Y34, the 3TK2826 expects
a +24 V DC signal from the same current source as the one from which the device receives its
power supply (possible only in the case of 3TK2826-*BB40) or from T3 (24 V DC).
In the case of the 3TK2826-*CW30 variant, it is imperative to connect the terminal T3 to the
floating sensor contacts due to the electrical isolation of the input circuit and sensor supply.
2
Evaluation
In addition to 2-channel connection of the same types of sensor contacts (NC/NC), sensors
with opposite types of contacts (NC/NO), as are frequently used in the case of electromagnetic
switches, can also be evaluated. Make sure that the normally closed contact is connected to
Y12, and the normally open contact to Y22.
3
Type of
connection
•
1 sensor with 2 contacts (1x2-channel) (NC/NC).
It is expected that both contacts are opened simultaneously.
•
2 sensors with one contact each (2x1-channel) (NC/NC).
It is expected that both sensors are AND-connected. Simultaneity is not monitored.
4
Debounce
time
Any change in the sensor signal during the debounce time is not evaluated.
•
50ms debounce time: switch position changes of strongly bouncing contacts are
suppressed (e.g. position switches on heavy protective doors).
•
10ms debounce time: the shorter debounce time permits faster deactivation of bounce-free
sensors (e.g. light arrays).
5
Start mode of
sensor input
•
Autostart: The enabling circuits are switched to the active position as soon as the switch-on
condition is satisfied at the sensor inputs Y12, Y22, Y34 and 1. The start button connection
terminal Y33 is not queried.
•
Monitored start: The enabling circuits are switched to the active position as soon as the
switch-on condition is satisfied at the sensor inputs Y12, Y22, Y34 and 1 and the start
button at the terminal Y33 is actuated (start with the falling edge).
6
Start mode of
cascading
input
•
Autostart: The enabling circuits are switched to the active position as soon as the switch-on
condition at the cascading input 1 is satisfied, i.e. as soon as a static
+24 V DC signal is present (e.g. from T3).
•
Monitored start: The enabling circuits are switched to the active position as soon as the
switch-on condition at the cascading input 1 is satisfied, i.e. as soon as a 24 V DC
signal is present (e.g., from T3), and the START button at terminal Y33 has been actuated
(start with falling edge).
7
Startup testing After a power failure, startup testing requires that the system operator actuates the sensors at
Y12 and Y22 once.
