The National Instruments OP-8913 Digital I/O Module is a high-performance, 32-channel solution designed for switch load signal conditioning (SLSC). It features 16 LVTTL/TTL digital input channels and 16 digital output channels, equipped with advanced fault insertion capabilities. The module allows users to configure channels as sourcing, sinking, or push-pull inputs and as either sourcing or sinking outputs. With rear transition interfaces and compatible cabling, the OP-8913 is suitable for use in various industrial applications with both PXI and CompactRIO systems.

A notable aspect of the OP-8913 is its integrated Fault Insertion Unit (FIU), which includes a total of 112 relays—seven relays dedicated to each differential signal pair. Each relay is independently adjustable, providing users with precise control over fault management. The FIU can simulate user-supplied voltage references (VBusA and VBusB) and generates various fault conditions such as open-circuit and short-circuit scenarios, facilitating comprehensive digital I/O system testing and validation.

Safety features inherent in the OP-8913 ensure reliable operation; relays are open by default, and all channels are updated simultaneously to prevent short circuits when VBusA and VBusB are not connected to the same channel. The design allows only one additional fault on a channel pair when Signal + and Signal - are shorted, and ensures safe transitions by keeping relays open before initiating new connections. With a relay response time of under 0.5 milliseconds, this module delivers high-density performance. However, to manage potential peak currents that may occur due to circuit capacitance, users must incorporate resistors into their setup. The VBus has a power supply limit of 0.1A, but caution is required to prevent transient peaks exceeding 5A, which could lead to relay damage. In the event of a relay failure in short mode, users can request a Return Material Authorization (RMA) for card repair.

The OP-8913 stands out as a versatile and reliable choice for digital I/O applications requiring robust fault insertion features and fast response times.