Topic:

I have connected the supply voltage to “Power supply” (X1) of an “EPOS4 ... 60/20,” but the LEDs are not lit and "EPOS Studio" cannot establish communication with the EPOS4 either.

• Have “Power supply” (X1) as well as “Logic supply” (X2) of the “EPOS4 ... 60/20” to be connected to a supply voltage?

resp.

• Should it be sufficient just to connect "Power supply" (X1) as this is possible for other EPOS4 product types? 

Solution:

The "EPOS4 ... 60/20" product types demand to apply  "Power Supply" (X1) and(!!) "Logic supply" (X2). 

Ensure that the "Power supply" (X1) as well as the “Logic supply” (X2) connector of the "EPOS4 ... 60/20" is connected to a supply voltage.

Technical background:

In case of any "EPOS4 ... 60/20" product type an optional certified "Safety Card STO" (P/N 833720) can be added. The "EPOS4 Module 60/20 STO" (P/N: 833726) and the "EPOS4 Compact 60/20 STO" (P/N: 894249) have the optional “Safety Card STO” already integrated at the factory.

The power supply for the internal logic circuits and the power output stage is fully separated from each other in case of an "EPOS4 ... 60/20". This means that a supply voltage has to be connected to "Power supply" (X1) and "Logic supply" (X2) as well.

Please refer to the information in ”EPOS4 Module-Compact 60/20 Hardware Reference":

• Power supply X1:
  
   

  If just "Power supply" (X1) is connected but "Logic supply" (X2) is missing, there is no voltage present for EPOS4's processor operation which means that ...

  • ... no data, I/O processing, and bus communication is possible.
  • ... no LEDs lit up.
• Logic supply X2:
  
  If just "Logic supply" (X2) is connected but "Power supply" X(1) is missing, EPOS4's processor will work and communication can be established but it is ...
  • ... not possible to enable the power stage (which demands for the "Power supply" (X1) voltage). 
  • ... a "Undervoltage error" (0x3220) is reported when the power stage is enabled.
     

Remarks:

• All other EPOS4 product types power the logic components via "Power supply" (X1) too, if "Logic supply" (X2) is missing. This is not possible for the "EPOS4 ... 60/20".
• Please check the "Hardware Reference" for the specified supply voltage range: