Description
Product Introduction
The National Instruments cFP-DO-400 is an 8-channel sourcing digital output module designed for the Compact FieldPoint distributed I/O platform. Its purpose is to switch external DC loads from a FieldPoint control system. NI specifies a 5–30 VDC output range, making the module suitable for a range of industrial discrete-control applications.
Each output channel provides a sourcing function, meaning the module supplies positive voltage to the connected load when the channel is commanded ON. Typical loads include relays, solenoids, contactors, lamps, and PLC input circuits. The module includes individual output-state LEDs, along with POWER and READY indicators, which are useful during cabinet commissioning and fault diagnosis.
The cFP-DO-400 is part of the older Compact FieldPoint product family. NI now marks it as no longer available and recommends the NI-9472 as a replacement within the newer CompactRIO/C Series ecosystem. The replacement should not be assumed to be a drop-in hardware substitute; terminal-base, software, wiring, and system architecture need to be checked.
Technical Specifications
| Parameter | Specification |
|---|---|
| Manufacturer | National Instruments |
| Model | cFP-DO-400 |
| Part Number | 777318-400 |
| Platform | Compact FieldPoint |
| Product Type | Digital Output Module |
| Number of Channels | 8 |
| Output Type | Sourcing |
| Voltage Range | 5–30 VDC |
| Output Impedance, 10–30 V | 0.3 Ω |
| Output Impedance, 5–10 V | 2 Ω |
| Max. Current/Channel, 10–30 V | 1.5 A at -40 to 50 °C; 1.0 A at higher specified temperature ranges |
| Max. Current/Channel, 5–10 V | 0.67 A |
| All-Channel Current, 10–30 V | 8 A at -40 to 60 °C; 4 A at 60–70 °C |
| Indicators | POWER, READY, 8 output-state LEDs |
| Operating Temperature | -40 to 70 °C |
| HotPnP | Yes |
| Transient Protection | 2,300 Vrms |
| Channel-to-Channel Isolation | None |
| Product Status | Discontinued |
The output-current limits are temperature dependent and should be checked against the actual load profile.
Main Features and Engineering Considerations
Eight Sourcing Outputs
The cFP-DO-400 provides eight independently controlled digital outputs. Unlike a sinking output module, a sourcing output supplies the positive side of the field circuit when activated. This distinction must match the wiring design of the connected equipment.
5–30 VDC Output
The wide voltage range allows the module to work with different DC field loads. At 10–30 VDC, NI specifies a low output impedance of 0.3 Ω, while the impedance is higher at the lower 5–10 V range.
CFP-DO-400
High Current Capability
The module can handle substantial DC loads for a compact FieldPoint output module, but the allowable current depends on both output voltage and ambient temperature. At 10–30 VDC, the per-channel rating falls from 1.5 A in the lower temperature range to 1.0 A at higher temperatures.
This makes thermal assessment important when several channels are simultaneously driving high-current loads.
HotPnP and Diagnostic LEDs
The module supports HotPnP, allowing it to be detected and identified automatically by the FieldPoint configuration software. Each output also has a dedicated LED showing its ON/OFF state, providing a quick first-level diagnostic indication.
Application Scenarios
The NI cFP-DO-400 is suitable for legacy Compact FieldPoint applications involving:
- Solenoid control
- Relay and contactor control
- Valve actuation
- Lamp and indicator control
- PLC discrete-input interfacing
- Industrial machine control
- Process automation
- Test and measurement equipment
- Distributed digital I/O
The module was specifically designed as a sourcing digital-output device for Compact FieldPoint.
Engineer’s Guide: Field Pitfalls
⚠️ Sourcing versus sinking matters.
The cFP-DO-400 is a sourcing output module. Do not substitute a sinking-output module without reviewing the field wiring.
⚠️ Do not use the 1.5 A figure without checking temperature.
At 10–30 VDC, the maximum per-channel current is temperature dependent.
⚠️ Watch total module loading.
The all-channel current limit also changes with temperature. Simultaneously loading all eight channels at their individual maximums may exceed the permitted aggregate current.
⚠️ No channel-to-channel isolation.
The output channels share a common electrical reference. This matters when connecting loads from different external circuits.
⚠️ Verify the terminal base and FieldPoint architecture.
This is a Compact FieldPoint module, not a standalone C Series module.
⚠️ Do not assume NI-9472 is a physical drop-in replacement.
NI identifies the NI-9472 as the suggested replacement, but the NI documentation describes it as a newer C Series module. System-level compatibility must be evaluated before a retrofit.
Frequently Asked Questions
What is NI cFP-DO-400?
It is an 8-channel sourcing digital output module for Compact FieldPoint.
What is the NI part number?
777318-400.
What voltage does it support?
The specified output range is 5–30 VDC.
How many outputs does it have?
Eight digital outputs.
Is it sourcing or sinking?
It is a sourcing digital-output module.
Is cFP-DO-400 still manufactured by NI?
No. NI currently lists it as no longer available. NI suggests the NI-9472 as a replacement.
What should be verified before purchasing?
- cFP-DO-400
- 777318-400
- Eight-channel configuration
- Sourcing output requirement
- Field voltage
- Per-channel load current
- Aggregate load current
- Ambient cabinet temperature
- Compact FieldPoint terminal base
- Channel-by-channel output test
Procurement note: For a used or refurbished cFP-DO-400, I would require an output-load test rather than accepting a simple power-on test. The temperature-dependent current ratings and discontinued status make actual channel testing important.
