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National Instruments 777687-20 Terminal Block 

Part Number 777687-20 is the identifying part number for the National Instruments SCXI-1320 Terminal Block. The terminal block is compatible with SCXI-1120/D (8 input channels), SCXI-1121 (4 input channels and 4 excitation channels), SCXI-1125 (8 input channels) and SCXI-1126 (8 input channels). The 777687-20 uses LM35CAZ IC as the cold-junction temperature sensor. The cold-junction sensor has an output range of 0 to 0.5 VDC from 0 to 50 °C i.e. (10 mV/ °C.). Similarly, the sensor has a repeatability of ±0.5 °C from 35 to 50 °C. Furthermore, it has an accuracy of ±1.3 °C from 0 to 50 °C with a maximum temperature gradient between the sensor and any terminal equalling ±0.4 °C (non-isothermal).

As for the maximum working voltage, each channel of the terminal block must remain within 300 Vrms or ±300 VDC of ground. This is also true for channel to channel, which means each channel must remain within 300 Vrms or ±300 VDC of voltage applied to any other channel. The module features DC coupling, allowing the passage of both AC and DC signals. The terminal block features 16 screw terminals for signal connections, which come in 8 pairs. Likewise, there are 2 functional ground terminals. The maximum wire gauge supported by the terminals is 16 AWG while the terminal spacing is 0.5 cm from center to center. Furthermore, it features a single safety earth-ground lugs and a strain-relief bar while there are no solder pads for additional components. 

The terminal block measures (7.0 by 3.125 by 1.2 in.) in physical dimensions and weighs 7 oz. The 777687-20is recommended for operation between temperatures of 0 to 50 °C with a relative humidity of 10% to 90%. On the other hand, it can be stored at a wider temperature range of -20 to 70 °C. The maximum altitude of the operation for the module is 2,000 m with an indoor pollution degree of  2. The terminal block complies with the requirements of safety standards of IEC 61010-1, UL 3111-1, and CAN/CSA C22.2 No. 1010.1.