User manual

915U-2 Wireless I/O Page 31
Page 31 User Manual
2.5.5 Digital Outputs (Pulsed Outputs)
Digital outputs are open-collector transistors and are able to switch loads up to 30VDC,
200mA.
The 8 digital outputs share the same terminals as the digital input. These terminals are
marked DIO1-8.
_
+
Max 30VDC
0.2A
V-
DIO1
DIO2
Common
915U-2
Discrete Input / Output Used as output
DC Load
Figure 15 – Digital Output Wiring
When active, the digital outputs provide a transistor switch to EARTH (Common).
To connect a digital output, refer to “Figure 15” above. A bypass diode (IN4004) is
recommended to protect against switching surges for inductive loads such as relay
coils.
The digital channels DIO1-4 on the 915U-2 module can be used as pulse outputs with a
maximum output frequency of 1 KHz.
Digital Output Fail Safe Status
As well as indicating the Digital Output status (on / off), the LEDs can also indicate a
communications failure by flashing the Output LED. This feature can be utilised by
configuring a Fail Safe time and status on the “I/O Configuration” web page as shown
below.