National Instruments 778572-68 SPST PXI Relay Module

The part number 778572-68 from National Instruments is the identifying part number for the PXI-2568 SPST PXI Relay Module. This module has 31 Electromechanical, latching SPST relays which allows this module to connect to a single input to a single output depending on the control signal. The module has a Form A latching design which means the switches integrated are Normally Open switches when inactive. The  778572-68 PXI Relay Module also has 15 double-pole, single-throw (DPST) switch configuration that offers the ability to control two separate circuits simultaneously. However, both poles within this configuration act in unison; when the switch is actuated, both poles simultaneously open or close their respective circuits.

The maximum voltage that can be switched between the channels is 150 Volts also the maximum voltage between a channel and ground is rated at 150 volts with a Category I safety rating. Category I typically refers to measurements performed on circuits not directly connected to mains, or transient overvoltages are unlikely to occur. The channels on this module are designed to support a maximum switching power of 60 watts or 62.5 VA. The channels can carry a maximum of 2 Amperes of current, exceeding the limit may cause permanent damage to the module. 

The relays usually take 1 ms to change their states but can also take a maximum of 3.4 ms. The maximum switching speed of the relays is approximately 145 cycles/s meaning the module is capable of changing the relay states 145 times in a second. The mechanical life of the relay is 1 × 108 cycles while the electrical life of the switches at 10 Volts is 2.5 × 106 cycles. 

To control the switching of the relays the module uses 7 memory-addressable trigger lines and requires a pulse width of 150 ns to activate or deactivate the switch. The power requirement to operate this module is 6 Watts at 5 Volts or 2.5 Watts at 3.3 Volts. This module has dimensions of 21.6 cm × 2.0 cm × 13.0 cm (8.5 in. × 0.8 in. × 5.1 in.) and weighs approximately 227 g (8 oz).