The National Instruments BNC-2140 is a Dynamic Signal Acquisition (DSA) Signal Conditioning Accessory designed to enhance the functionality of National Instruments' dynamic signal acquisition devices. This product allows for seamless integration with devices such as the PCI-4451, PCI-4452, PCI-4551, and PCI-4552 by interfacing two BNC signal outputs with four BNC signal inputs. It is compatible with IEPE microphone preamplifiers, accelerometers, and other sources with voltage levels below ±42.4 V. Each input channel features a dedicated 4 mA current source, making it ideal for various IEPE sensors. The BNC-2140 supports independent enabling or disabling of signal conditioning on each channel, providing versatility in operation. It offers selectable analog input modes, allowing for single-ended (SE) or differential (DIFF) configurations, without affecting the operation of the IEPE signal conditioning. Additionally, the analog outputs can operate in either DIFF or SE mode, and manual switching between these modes is straightforward. The BNC-2140 features six BNC connectors and a 68-pin VHDCI female connector, ensuring robust connections between the DSA device and the accessory. While National Instruments has announced that the BNC-2140 is now obsolete, it remains available for purchase and repair through Apex Waves. Technical specifications include four voltage input channels, two analog output channels, a power consumption of 400 mA at +5 VDC, and dimensions of 5.7 by 4.4 by 2.2 inches. Comprehensive user and maintenance manuals are also available for download. For pricing, please contact a sales representative for a quote.