User's Manual

Rockwell Automation Publication 440G-UM004C-EN-P - August 2020 23
Chapter 4 Wiring and System Integration
Lock Command
OSSD Mode
Table 9 shows the lock command function. The lock command is a 24V logic
signal with a current of less than 2 mA. The function of the logic signal is
dependent on the catalog number.
Catalog codes for both types are explained in Table 4 on page 9
.
GuardLink Mode
In a GuardLink system, the GuardLink safety master (for example a DG safety
relay) issues lock and unlock commands to the 440G-MZ safety switch via the
GuardLink Control, Lock, and Unlock (CLU) signal. This signal is either static
or dynamic. When static, this signal is LO when the system is operational and
HI when a demand is placed on the safety system. The signal is dynamic when
an unlock or lock command is issued to the 440G-MZ safety switch.
When multiple guard locking devices are installed in a GuardLink system, the
GuardLink safety master inserts a short delay between commands to each
successive device to minimize the momentary inrush current to the solenoids.
The device closest to the master receives the command first. The device
furthest away from the master receives the command last.
See publication 440R-UM015
for more information.
Table 9 - Lock Command Function
Cat. No. Function Value
440G-MZS20*MR* Power to Release
24V = Unlock
0V = Lock
440G-MZS20*ML*Power to Lock
24V = Lock
0V = Unlock