Delta RMC151 - Manual (Page 1181)

10 Wiring and Installation
Figure 7: Open Collector Outputs to the DI/O Module Inputs with Input Common
Connected to Ground.
For 24VDC power, the pull-up resistor should be a 3.3 kΩ, 1/2 watt resister. The output
must be capable of switching 7.5mA when closed. When the open collector output is
open, the DI/O input sees 7V @ 5.1mA.
For 12VDC power, the pull-up resistor should be a 560 Ω, 1/8 watt resister. The output
must be capable of switching 9.0mA when closed. When the open collector output is
open, the DI/O input sees 3.1V @ 3.4mA.
Dividing the Input Voltage
Because the DI/O module inputs are designed for use with 5V outputs, the threshold is
2.75VDC. This is a small percentage of the 24V outputs. As a result, it is important that
the inputs have very little noise. This section describes using a voltage divider to raise the
apparent input threshold.
Note: Before resorting to dividing the input voltage, take all possible measures to eliminate
noise from the inputs.
To divide the inputs, attach resisters to each input as shown in the following diagram:
This configuration will reduce noise susceptibility by a factor of about five.
10.3.10. RMC150 UI/O Wiring
This topic covers the wiring of the discrete inputs and outputs on the RMC150 UI/O module
(UI/O or U). See Wiring Guidelines for general wiring information.
Wire clamp screws must be tightened to max 2.2 lb-in (0.25 Nm).
UI/O Analog Inputs
Wire the analog inputs according to the RMC150 Analog Wiring topic.
UI/O Discrete Outputs
The UI/O points configured as outputs are solid state relays. When they are ”off” they
have high impedance, and when ”on” they have low impedance (50Ω maximum, 25Ω
typical). The user must power the outputs externally. The maximum current and voltage
for the outputs is 75 mA (50 mA for Class I, Div 2) and 30 V.
deltamotion.com 1161