Digital Input and Output (DIO) is the most popular interface used to communicate and interact with external instruments. Each digital input and output channel has only two states, high and low. The Spider can respond to the state of a digital input channel from an external instrument (e.g., an amplifier, an analyzer) or send a digital output to an external instrument to urgently shut down a device.
The DIO change of the state is directly managed by the DSP without an additional exchange of commands to achieve the shortest response time. It is ideal for applications that require an immediate response from external equipment or a Spider system working as a shutdown protection system.
The EDM 10.1 release software provides users a convenient view of the digital output status without the need to measure or check additional devices. Users can display and manually change the state of digital outputs by navigating from the View menu to the Digital Output Live View window.
Select output: select a digital output and change its state. The ALL output option is included to set all outputs at the same time.
Digital output signal pattern: select an output pattern to generate
Apply DIO setting: apply settings to the selected digital output
Connector illustration: pin numbers correspond to the physical connector. The illustration is different according to different connector types. Crystal Instruments products adopt DB-25, DB-15, or DB-9 connectors. When the state of a digital output is high, the pin number turns black. When the state is low, the pin number is white.
An example of the DB-25 connector on the back of Spider-81 vibration test controller.
An example of the DB-9 connector on back of Spider-80Xi/80M vibration test controller.
The pin with the EX_PWR label must connect to a power source that provides power to the digital output interface. The power source can be built-in or external.
The pin with the EX_GND label must connect to the ground of the power source.
The pin with the +12 V label is a built-in power source in the vibration controller to power the digital output interface.
The pin with the GND label is the ground of digital output pins and +12 V power.
A convenient solution is to power the digital output interface with the built-in 12 V power source and eliminate the hassle of connecting to an external power. However, the high state of the digital output is the same as internal power at 12 V.
Applications requiring different voltages for the high state of the digital output requires an external power source at the desired voltage.
Digital output window: displays the live status of all digital outputs
Right-click on the digital output window to access its display properties. A longer display time duration provides the history of the digital output state. Assigning a color to each digital output helps users to differentiate and relate a digital output to an external device.
Connecting DIO breakout box to a relay
The DIO breakout box for Spider products is designed to easily connect the Spider DIO interface to an external device. Users do not have to deal with pin numbers on the DIO connector. DIO connectors on CI Spider products are three types: DB-21, DB-15, and DB-9. The breakout box supports all three types of connectors.
Using an internal power source
The digital input/output circuit on the Spider system can be powered by an internal DC power source at 12 volts.
The Spider system provides 12 V to the digital output circuit so the power of the relay coil must be 12 V to result in a voltage difference over the relay coil at zero or 12 V to control the switch.
Using an external power source
An external power source allows users to change the voltage of the HIGH digital output signal. The breakout box supports 12~24 volts from an external source. If the relay requires 0 or 18 V difference over the relay coil to control the switch, then an external power source must be used.
Use the switch on the breakout box to accept an external power source. Then connect an 18 V source. The digital output signal High will be identical to the external power source. The following diagram shows the external power provided at 18 V DC and the high state of the digital output to be +18 V.
