NI 9478 (FPGA Interface)
CompactRIO 16-Channel, 0–50 V Sinking Digital Output Module with Programmable Current Limits
FPGA I/O Node
You can use an FPGA I/O Node, configured for writing, with this device.
Terminals in Software
Use the FPGA I/O Node to access the following terminals for this device.
| Terminal | Description |
|---|---|
| DOx | Digital output channel x, where x is the number of the channel. The NI 9478 has DO channels 0 to 15. |
| DO7:0 | Digital port consisting of channels 0 through 7. Channel 7 is returned in the MSB, and channel 0 is returned in the LSB. |
| DO15:8 | Digital port consisting of channels 8 through 15. Channel 15 is returned in the MSB, and channel 8 is returned in the LSB. |
| DO15:0 | Digital port consisting of channels 0 through 15. Channel 15 is returned in the MSB, and channel 0 is returned in the LSB. |
Arbitration
This device supports only the Arbitrate if Multiple Requestors Only option for arbitration. You cannot configure arbitration settings for this device.
Module Methods
Use the FPGA I/O Method Node to access the following method for this device. This device does not support any I/O methods.
| Method | Input/Output | Description |
|---|---|---|
|
Check Output Status |
Limit Selection | Specifies which current limit status information the module reads. Select Active Limit if you want the Channel Overcurrent output to return TRUE for any channels that exceed the current limit threshold specified for the active current limit for that channel. Select Limit A to return TRUE for any channels that exceed the current limit threshold specified for Current Limit A. Select Limit B to return TRUE for any channels that exceed the current limit threshold specified for Current Limit B. |
| Module Overtemp | Returns a Boolean value. A value of TRUE indicates that the module exceeded its temperature rating. | |
| Channel Overcurrent | Returns an array of Boolean values. A value of TRUE in any index indicates that the channel sharing a number with that index exceeded the current limit, as specified by the Limit Selection input, after the last status read. A value of FALSE indicates that the channel did not exceed the current limit after the last status read. |
Module Properties
Use the FPGA I/O Property Node to access the following properties for this device. This device does not support any I/O properties.
| Property | Description |
|---|---|
| Active Current Limit | Sets the active current limit for each channel. The value in an index of the input array controls the active current limit for the channel sharing a number with that index. Select No Change if you do not want to modify the active current limit for the channel at run time. Select Limit A if you want to set the active current limit for the channel to Current Limit A. Select Limit B if you want to set the active current limit for the channel to Current Limit B. Select No Limit if you want the channel to have no current limit. |
| Current Limit A | Sets the current limit threshold for Current Limit A in binary values. You can use the following equation to calculate the binary value from amperes: Binary Value = (Current Value / 5.12 A) × 256 The range of valid current limit values is 0–5.1 A, which corresponds to binary values 0–255. |
| Current Limit B | Sets the current limit threshold for Current Limit B in binary values. You can use the following equation to calculate the binary value from amperes: Binary Value = (Current Value / 5.12 A) × 256 The range of valid current limit values is 0–5.1 A, which corresponds to binary values 0–255. |
| Module ID | Returns the module ID. |
| Overcurrent Refresh Period | Sets the time in µs it takes a channel to automatically recover if the channel exceeds its active current limit threshold. Values 2–255 enable overcurrent refresh and specify the time in tens of µs. For example, a value of 3 sets an overcurrent refresh period of 30 µs. A value of 0 disables overcurrent refresh so the channel remains disabled after exceeding its active current limit until you write to the channel using an FPGA I/O Node. A value of 1 is not supported and sets an overcurrent refresh period of 20 µs. |
| Serial Number | Returns the unique serial number of the module. |
| Vendor ID | Returns the National Instruments vendor ID, 0x1093. |
Single-Cycle Timed Loop
This device does not support the single-cycle Timed Loop.
Hardware Documentation
Refer to the NI 9478 Operating Instructions and Specifications to learn about module specifications and how to use the module. Refer to the CompactRIO Related Documentation for further information about CompactRIO documentation.