National Instruments SCXI-1304 AC/DC Coupling Terminal Block

The SCXI-1304 (Part Number: 777687-04) is a Terminal Block from the SCXI Series by National Instruments. This AC/DC Coupling Terminal Block can be used with the SCXI-1140, SCXI-1141/1142/1143, SCXI-1120/D, and SCXI-1125 modules. Other than AC/DC Coupling, this model also has BNC connectors and signal ground referencing which can be configured for each channel. There are 22 screw terminals on the NI SCXI-1304 for effortless signal connection. The user can utilize eight pairs of screw terminals for signal connections to the eight module inputs and a single pair to link to the module analog ground. The other four screw terminals give access to the digital ground and digital signals of the module. For the SCXI-1140, these signals are HOLDTRIG. However, for the SCXI-1141/1142/1143, these signals are OUTCLK and EXTCLK.

When the National Instruments SCXI 1304 Terminal Block is used with the SCXI-1120/D, SCXI-1125, or SCXI-1126, the channel isolation specification is not valid if the bias resistors are in the engaged setting. The user must keep the resistor switches in the open or G grounded setting, so the isolation remains valid.

The NI SCXI-1304 has the capability for every channel to be configured for AC or DC coupling via the switch settings. Every channel needs two switches in identical positions for the coupling circuitry to work accurately. For AC coupling, the user must designate both switches to the AC setting, which puts single-pole highpass filters in the paths of the positive and negative channel inputs. On the other hand, for DC coupling, the user must set both switches to the DC position. This eliminates the filters from the signal paths and links the screw terminals straight to the module inputs.

 It has recommended operating and storage temperature ranges of 0 to 50 °C and –20 to 70 °C respectively, and a non-condensing relative humidity range of 10 to 90%. The SCXI-1304 is designed to comply with the following electrical safety standards: IEC 61010-1, EN 61010-1, UL 3111-1, UL 61010B-1, and CAN/CSA C22.2 No. 1010.1.

SCXI-1304 Obsolete Status has been announced by National Instruments, but the Terminal Block will still be available for purchase and repairs by Apex Waves.