National Instruments 779517-01 C Series Digital Module

Commonly referred to as the NI-9477, the 779517-01 is a multipurpose 32-channel sinking output digital module from National Instruments. Because of its proficiency with industrial logic levels and signals, this module can be directly connected to a wide range of industrial devices, including motors, solenoids, and relays. Its 32 channels each have isolation between the channel and the earth ground and can handle signals between 5 and 60 volts. The 779517-01 can sink current up to 20 A per module, with a maximum of 1 A per channel. By wiring channels in parallel, this maximum can be raised.

Each channel of the 779517-01 includes a digital output (DO) pin for connecting digital input devices, and the module also features four common (COM) pins. When a channel is activated, its DO pin is driven to COM, reflecting its sinking output nature. With a continuous output current of 1 A per channel, the module supports parallel channel connections to boost the output current to connected devices.

To help save energy while the module is not in use, it enables low-power sleep mode, which can be used based on the chassis it is linked to. With an external power supply voltage range of 0 to 60 VDC and a strong output impedance of 0.065 Ω maximum, the 779517-01 is designed to withstand industrial settings. However, it does not feature reversed-voltage or short-circuit protection, so these conditions must be managed externally.

In terms of performance, the 779517-01 ensures quick response times in control applications with a maximum update rate of 8 μs and a propagation latency of just 1 μs. The module contributes to up to 1.5 W of thermal dissipation at 70 °C in active mode, with an efficient power consumption of only 25 μW in sleep mode and a maximum of 650 mW in active mode.