• Mounting rack for 24 solid state relay (SSR) modules (backplane is divided into two groups of eight modules and two groups of four modules)
• Onboard switch to configure the module type (input or output) for each module group
• Onboard switch to configure the control logic polarity (active high or low) for each module group
• Onboard switch to configure the power-up state for output modules
• Switch settings can be read back with software

The Digilent MCC USB-SSR24 can monitor and control 24 standard size solid state relay (SSR) I/O modules (relays sold separately). SSR digital I/O modules are relay control modules that provide 4000 Vrms of optical isolation. Digital input modules sense AC/DC voltages from field devices and convert them to digital TTL signals. Digital output modules use TTL signals to switch and control AC/DC loads.

The USB-SSR24 provides mounting locations for 24 SSR modules. The device comes in in a heavy-duty metal enclosure with integrated mounting slots, which ensures that it is rugged enough for any DAQ application. The USB-SSR24 is powered by an external 9V regulated power supply that is shipped with the device.

Software support includes DAQami, an optional out-of-the-box application for data logging, visualization, and signal generation. Data can be viewed in real-time or post-acquisition on user-configurable displays. Drivers are included for the most popular applications and programming languages including Visual C++, Visual C#, Visual Basic.NET, DASYLab, LabVIEW, Linux, and Python.

The USB-SSR24 functions are illustrated in the block diagram shown below.