Measurement Computing USB-ERB24 - Manual (Page 8)

Chapter 1
Introducing the USB-ERB24
Overview: USB-ERB24 features
This user's guide contains all of the information you need to connect the USB-ERB24 to your computer and to
the external devices you want to control. You can use the USB-ERB24 in your control applications to switch on
and off a variety of devices, such as fans, blowers, pumps, etc.
The USB-ERB24 is a USB 2.0 full-speed electromechanical relay module supported under popular Microsoft ®
Windows ® operating systems.
The USB-ERB24 has 24 single-pole double-throw (SPDT) Form C electromechanical relays. The digital I/O
lines on your MCC USB Series board directly control the relays on your USB-ERB24.
You connect your field wiring directly to the board's screw terminals. The screw terminals provide three
connections to each relay – normally open (NO), normally closed (NC), and common (C).
You can configure the logic polarity and power-on state of each bank of relays with on-board switches. The
relays are configurable as two banks of eight and two banks of four. Switch settings can be read back with
software.
The USB-ERB24 is powered by an external 9 V, 3 A regulated power supply that is shipped with the device. A
USB cable is also included. Power OUT and USB OUT connectors let you power and control multiple MCC
USB Series boards from one external power source and one USB port in a daisy chain fashion. Depending on
your load requirement, daisy chained boards may require a separate power supply.
The USB-ERB24 is enclosed in a rugged housing that you can mount on a DIN rail or on a bench (Figure 1-1).
Figure 1-1. USB-ERB24
1-1