Siemens Tm-e15C26-a1 Simatic Terminal Module Autronica GT-24/B/GE-3 What does guard locking mean

What does guard locking mean in this switch

• Energy Efficiency: Works on DC 24V

and give alarm to operators in case there are any problems

Attribute Value Brand Daiichi Model SD-HH-63 Product Type DC Sensor Part Number TP-357D Input Voltage DC 130 V Auxiliary Supply (1-2) DC 24 V Auxiliary Supply (1-3) Not Specified Set Point H2 DC 50~100 V Set Point H1 DC 10~30 V Manufacture Location Chiba Serial/Date Code 0819202022 Approximate Weight 500 gm

• Wide Voltage Range: 450V AC supply for the 1-3 phases and 400V AC supply for the 2-3 phases

Siemens Tm-e15C26-a1 Simatic Terminal Module Autronica GT-24/B/GE-3 What does guard locking meanSiemens Tm e15C26 a1 Simatic Terminal Module Siemens Simatic Terminal Module Tm e15C26 a1 6Es7 193 4Ca50 0Aa0 Made In Germany Weight: 150 Gm