Eight open-collector outputs, DO1–DO8, in the field domain.

Parameter

Value

Type

Optocoupler, Darlington open collector, sinking to field ground

Isolation domain

Field

Load supply

≤ 24 Vdc

Output current

25 mA per output†

Total output current

200 mA for all eight outputs together†, through the shared field ground

Saturation voltage

About 1 V at full load (Darlington output)†

Isolation rating

2500 Vrms, 1 minute (optocoupler component rating)

Wiring

Connect the load between the field supply positive and the output terminal. The output pulls the terminal down to field ground when active.

Inductive Loads 

Fit a flyback diode across any relay, solenoid or valve coil driven from these outputs. There is no clamp on the board, and the optocoupler output transistor will be damaged by the inductive flyback voltage without one.