USB module for controls with optocouplers and relays

Bipolar inputs with optocouplers and power outputs via relays

The inexpensive EXDUL-337S USB module for controls has 12 digital bipolar optocoupler inputs and eight relay outputs with potential isolation. The optocoupler inputs are secured with additional overvoltage protection diodes. The switching current of the relays is a maximum of 2 A per channel. Contact A of the relay is connected to one terminal each, contact B is brought together on a common terminal for all 8 channels.

Optocoupler inputs can be used as counters

If required, six of the 12 optocoupler inputs can also be used as hardware-supported 32-bit counter inputs with a maximum input clock of 5 kHz. To prevent meter data loss in the event of a power failure, the meter readings are saved in the module at intervals of 100 µs and automatically loaded into the meter register when the module is restarted.

Communication via USB connection

The communication between the PC and the module takes place by sending and receiving byte arrays via the USB interface. This communication is secured by a handshake protocol.

Watchdog for secure communication

The EXDUL module has various security mechanisms. However, should the communication be interrupted, the module's integrated watchdog timer can be used to troubleshoot the problem.

Internal logic with module initiated messages

In various applications it can be advantageous if the module reacts independently to input signals or changes at the inputs. Without this option, a change at the input can only be detected by regularly querying the inputs using polling. This polling causes an increased load on the network and the computer. In order to generate this independent reaction of the module, four logic branches are provided, each with four logic inputs, a link and a logic output. This logic output can then be connected to a relay output or used for module-initiated messages to the PC.

Power supply

The module can be supplied with the necessary operating voltage via the USB interface or externally with a voltage between 10 and 30 volts.

Connection and assembly

The connections for the power supply, like the connections for the input optocouplers and output relays, are fed to a 24-pin screw terminal strip. The compact housing allows use as a mobile module on the notebook and as a control module in control and mechanical engineering with simple wall mounting or uncomplicated mounting on DIN EN mounting rails.

Software, drivers, programming languages

No driver is required for Windows® 10 or higher for the USB module EXDUL-337. The module is automatically recognized by the operating system. A driver is available for Windows&reg 7 and Windows&reg 8. A virtual COM driver is used for direct access to the module, which is supported by many high-level languages ​​such as C, C++, C# or Visual Basic.

Supported operating systems and programming languages

Microsoft Windows^®

VB.net^®, C++.net^®, C#.net^®, Labview Tutorial^®

Linux^®

C^®, C++^®