User's Manual

Rockwell Automation Publication 440G-UM004C-EN-P - August 2020 35
Chapter 7 Application Examples
Wire to DI and EMD
Safety Relay
The 440G-MZ safety switch can be connected to the DI and EMD safety relays.
The DI safety relay monitors the safety outputs of the safety switch and the
EMD enables the gate to be unlocked after a configured delay time expires.
B1 is connected to B2 to allow for retriggering. If you open and close the E-stop
and press Reset before the delay expires, the EMD timer resets.
Upon initial power-up, the safety switch must be cycled for the DI to recognize
the safety switch OSSD signals.
In the example shown in Figure 14
, an E-stop initiates the machine shutdown.
After an eight-second delay, the safety switch is allowed to be unlocked and the
hazards that remain are turned OFF. A selector switch is required to maintain
the gate in an unlock state. The risk assessment must determine adequate time
delay for the machine to achieve a safe state before unlocking the gate.
Figure 14 - DI Safety Relay with EMD Safety Relay and 440G-MZ Safety Switch Schematic
Circuit Status as Shown
The E-stop is released. The gate is open and unlocked. K1 and K2 are OFF. The
DI safety relay is configured for two inputs with monitored manual reset. The
EMD safety relay is configured for 8-second off-delay; Range setting of 2 is 10
s, Time setting of 8 is 80% of the range. The X32 terminal is ON because the
EMD safety outputs are OFF.
Power
In1
In 2
Out
Logic
A2
A1
L12
L11
13
14
23
24
IN1
DI
IN2
LOGIC
Test Out
A2
A1
B2 37 B1 47 48
38
L12
L11
X32
17
27
28
18
EMD
17
18
27
28
37
38
47
48
E-stop
K1
K2
M
K1
K2
Reset
Unlock
2
S11
S21
S12
S22 S32 S42
Y32 S34
TIME
8
RANGE
2
Brown
Blue
Gray
White Black
Brown = +24V DC
White = OSSD 1
Black = OSSD 2
Blue = 24V DC COM
Gray = Lock CMD
L1 L2 L3
440G-MZS20*NR*
+24V DC, Class 2, PELV
24V DC COM