DOC-0017-04-EN: AC20 Series - Hardware Installation Manual 
  DOC-0017-04-EN-A 22.03.2023   143 (154) 
 External +24V Auxiliary Input 
Allows for the partial power-up of the product without mains power applied, for programming of the drive 
using the DSELite programming tool through the Ethernet port, or communication with the drive through the 
Anybus Comms option. µSD Card port, display, keypads and digital I/O are also active.  
Input Voltage: 
24V +/-10% (up to a maximum ambient temperature of 40°C) 
24V +5 / -10% (up to a maximum ambient temperature of 45°C) 
Indicative Input Current: 
-  Control Board only: 45mA 
-  Control Board with EtherCAT comms option fitted only: 85mA 
Reverse Voltage 
Protection: 
No 
 
 STO Inputs 
STOA, STOB, referenced to 0V 
24V PELV (with energy source class 3, according to IEC 62368-1) 
Maximum Input Voltage: 
25.2V (26.4V in a maximum operating ambient of 40°C) 
Recommended Input 
Voltage for Logic Low 
Level: 
0V – 5V (or open circuit) 
Recommended Input 
Voltage for Logic High 
Level: 
15V – 24V 
Indetermined Input 
5V – 15V, function is undefined 
Always Active (i.e., STO cannot be disabled by the drive firmware) 
STO User Input A Logic 
0V or open circuit = STO Activated 
24V = STO Disabled 
STO User Input B Logic 
Level: 
0V or open circuit = STO Activated 
24V = STO Disabled 
Isolation: 
Channel A & B to SELV: Galvanic Isolation. 
Channel A to Channel B: Non-isolated