National Instruments 777687-38 Terminal Block 

National Instruments part number 777687-38 is an identifying part number for the SCXI-1338 a Current Input High-Voltage Terminal Block with DC Input Coupling, 16 AWG, and 16 Screw Terminals for signals. This terminal block mounts to the front of the SCXI module and is shielded for quick and easy signal connections. This instrument is an 8-Channel Current Input Terminal Block, ideal for high-precision current measurements. Each input channel is equipped with a 249 Ohm precision resistor, allowing for the measurement of 0 to 20 mA or 4 to 20 mA current inputs. 

The terminal block features 16 screw terminals for straightforward connections. Eight pairs of screw terminals connect to the eight module inputs, while the remaining pair connects to the SCXI chassis ground. This module features a resistance accuracy of ±0.1% and a temperature coefficient of 10 ppm/°C, ensuring precise measurements. It has a power rating of 0.25 W and includes a safety earth-ground lug. For added durability and secure connections, it is equipped with a strain-relief bar at the terminal block entrance. 

The maximum supported wire gauge is 16 AWG. The 777687-38 Terminal Block is capable of measuring both current and voltage sources. When measuring voltage signals, the current-loop resistor for the specific input channel must be removed. Each resistor is identified by a reference designator that corresponds to its respective channel. For instance, resistor R0 is associated with input channel 0. To set up and use the terminal block, you will need the following items: an SCXI chassis, one of the following modules—SCXI-1120, SCXI-1120D, SCXI-1125, or SCXI-1126, a number 1 and 2 Phillips-head screwdriver, a 1/8 in. flathead screwdriver, long-nose pliers, a wire cutter, and a wire insulation stripper.