Data Acquisition and Control Interface - DACI (9063)
The Data Acquisition and Control Interface (DACI) performs two main functions: data acquisition feeding raw signal data to the computer-based instruments, and data acquisition for implementing a control function. Each DACI can perform these two functions at the same time. However, when a complex control function is implemented, the DACI stops data acquisition for the computer-based instruments and performs only data acquisition for the control function.
All data acquisition is performed by an isolation unit and a microcontroller in the DACI. The isolation unit converts high-level voltages and currents measured in electric power systems and power electronics circuits into low-level, isolated analog signals, and routes these signals to the microcontroller. A/D converters built in the microcontroller convert the low-level analog signals into digital signals (data). The microcontroller routes these digital signals to the personal computer that runs the LVDAC-EMS software for measurement and display by the computer-based instruments. Another set of A/D converters built in the microcontroller convert some of the low-level analog signals from the isolation unit into digital signals (data) to implement the control function performed by the DACI. Depending on the control function implemented, the microcontroller produces analog or digital control signals. These control signals are routed to various output terminals on the front panel of the DACI.
The DACI has four isolated voltage inputs and four isolated current inputs. All these inputs are fitted with 4-mm banana safety jacks which makes connections to electric power circuits implemented with Lab Volt equipment quick, safe, and easy. The DACI also has eight low-level, software-programmable analog inputs which allow measurement of other circuit parameters. Two of these low-level analog inputs can be used for torque and speed measurements using a Lab Volt dynamometer (Model 8960-1 or 8960-2). Finally, the DACI is provided with three digital inputs which can be monitored through the LVDAC-EMS software. Two of these digital inputs are used as an incremental encoder input (A-B) and the third input is used for synchronization. The eight low-level analog inputs and the three digital inputs are all fitted with miniature (2 mm) safety banana jacks.
The DACI has a 7 bit digital output which can be used to control Lab-Volt power electronics modules like the IGBT Chopper/Inverter, Model 8837, and the Power Thyristors, Model 8841. This output can also be used to control other types of modules. The 7 bit digital output provides TTL-level signals on a 9 pin, D type connector. The DACI includes two additional single-bit digital outputs that also provide TTL level signals. The DACI also includes two software-programmable analog outputs which can be used to control a dynamometer or a power electronics module. The two single-bit digital outputs and the two analog outputs are all fitted with miniature (2 mm) safety banana jacks.
All inputs and outputs of the DACI are protected against improper connections and overvoltage/overcurrent conditions. The user guide included with the DACI provides detailed information about the module operation. Interconnection between the DACI and the personal computer running software LVDAC EMS is through a standard USB cable included with the module.
To activate the data acquisition for the computer-based instruments, a license for the Computer-Based Instrumentation Function, Model 9069-1, must be purchased for each DACI that will be used with the computer-based instruments. Similarly, to activate the data acquisition for a specific control function, a license for that specific function, Model 9069-X, must be purchased for each DACI that will be used to perform this control function.