Siemens eWON4002 - Manual (Page 20)

eWON4002™
Installation Guide
page 17 of 35
ver 2.04
5.6 Digital Outputs
There are 3 Digital Outputs: 1 open collector and 2 relays.
5.6.1 Open collector Digital Output
The open collector output is located on the Input/Output connector, which stands beside the power supply
connector.
This Digital Output is activated by an open collector transistor driven by an optocoupler. The maximum current flow
into this transistor has a characteristic above the value specified in the eWON®, in order to cope with the switching
power losses. The transistor used is of open collector type with pre drive. This means the relay power supply has to
be supplied from an external source to the pre drive electronics.
The diagram below shows the external wiring needed for correct operation of the Digital Output. A relay has been
chosen for this sample application but any load within the specifications can be used instead.
Warning: note that this is a sink only output to ground (the transistor acts like a switch to ground).
Figure 11: Digital output: wiring diagram
Specification Value
Type of output Open collector
Max current (external source) 200mA @ 30 VDC
Isolation 3,5 kV
Pinout connector See label and appendix ( Input/Outputs on page 28 )
Table 15: Open collector Digital Output specification