Data Translation DT9824, User Manual, Page: 54 / 102

Chapter 5
54
Digital I/O Features
The DT9824 module provides 8 digital input lines and 8 digital output lines that you can use
to control external equipment, including solid-state or mechanical relays.
This section describes the following digital I/O features of the DT9824 modules:
• Digital input lines, described below
• Digital output lines, described on page 54
• Channel-to-channel isolation, described on page 55
• Resolution, described on page 55
• Operation modes, described on page 55
Digital Input Lines
The DT9824 module features eight, isolated, digital input lines.
Digital inputs operate from +3 to +28 V DC, with a switching time of 2 ms maximum. Figure
15 shows the digital input circuitry; a 2.2 k
Ω
resistor is used in series with the LED in the
opto-isolator input.
Figure 15: Digital Input Circuitry
A digital line is high (switch is closed) if its value is 1; a digital line is low (switch is open) if its
value is 0.
Digital Output Lines
The DT9824 module features eight, latched and isolated digital output lines. The outputs are
solid-state relays that operate at ±30 V and 400 mA peak (AC or DC). Switching time is 2 ms
maximum.
Figure 16 shows the digital output circuitry.
Digital Input
+
-
2.2K