Description
Pacific Scientific 6440-001-K-N | 5.0A RMS Stepper Drive & Power Supply
Architect’s Product Breakdown
The Pacific Scientific 6440-001-K-N functions as a complete motion control hub, combining an internal 300 W switching power supply, an intelligent indexer, and a high-performance microstepping drive into a single enclosure. Instead of relying entirely on an external high-level motion controller, engineers can load custom motion profiles directly into its 1792 bytes of non-volatile RAM using simple single-letter mnemonic commands over serial links. It supports both fixed and variable resolution modes, dynamically altering step size on the fly to maximize velocity without sacrificing low-speed positioning accuracy.
Cabinet integration requires accounting for its larger physical footprint (6.25 by 2.25 by 12.5 inches) and direct off-line AC power routing. Thermal management is critical; while it features an internal switching supply and cooling layout, panel designers must maintain a 0 °C to 50 °C ambient operational range to prevent premature thermal fault tripping. Field retrofits demand careful mapping of the eight bi-directional discrete I/O lines and serial communication wiring (RS-232, RS-422, or RS-485), ensuring legacy control schemes translate correctly to the unit’s internal instruction registers.
6440-001-K-N
Key Technical Specifications
| Parameter | Specification |
| AC Input Voltage | 120 / 240 VAC, 50/60 Hz (Switch Selectable) |
| Internal Power Supply Rating | 300 W continuous |
| Continuous Phase Current | Adjustable from 0.625 A to 5.0 A RMS (in 0.625 A increments) |
| Peak Phase Current | 7.1 A Peak (Microstepping mode) |
| Secondary Axis Output (J6) | 66 VDC \pm2V ( feeds secondary slave drive) |
| Communication Protocols | RS-232, RS-422, RS-485 (9600 Baud) |
| User Memory | 1792 Bytes NVRAM for program storage |
| Microstepping Resolution | Binary: Up to 51,200 steps/rev; Decimal: Up to 50,000 steps/rev |
| Discrete I/O | 8 programmable bi-directional lines + dedicated start/stop/limit/home inputs |
| Enclosure Dimensions | 6.25 in x 2.25 in x 12.50 in |
| Operating Temperature | 0 °C to 50 °C ambient (derated up to 60 °C) |
| Weight | 6.0 lbs nominal |
Field Engineer’s Pitfall Guide
- WARNING: Live Secondary Bus Power Hazard. The J6 auxiliary connector outputs 66 VDC to power a secondary slave drive. Technicians disconnecting internal umbilical or daisy-chained cabling while the main AC breaker is closed risk shorting the auxiliary rail, which instantly fries the internal switching regulators.
- CAUTION: NVRAM Battery-Free Assumptions. While programs are stored in non-volatile memory, firmware parameters and custom register states can be overwritten during botched serial flash uploads. Always back up your mnemonic program strings externally before swapping control boards or performing firmware resets.
- NOTICE: Jumper-Configurable I/O Conflicts. The eight bi-directional discrete I/O lines must be physically configured via internal jumpers for input or output operation. Assuming default factory jumper states when integrating into an existing PLC thumbwheel or sensor layout will cause logic state mismatches and unresponsive machine commands.
QA & Testing SOP
- Visual & Origin Inspection: Inspected for OEM chassis labeling, structural integrity of the internal circuit boards, and secure placement of configuration jumpers.
- Live Test Bench Environment: Connected to a variable 120/240 VAC bench source to validate the internal 300 W switching power supply rails and logic core startup behavior.
- Communication & Memory Handshake: Serial ports (RS-232/485) are tested at 9600 baud to verify command-line responsiveness, program read/write cycles, and NVRAM data retention.
- I/O and Axis Simulation: Dedicated and programmable discrete I/O channels are exercised under load, checking optocoupler isolation and verifying the 66 VDC auxiliary output stability on terminal J6.
- Packaging: Antistatic wrapping and rugged industrial foam cushioning applied to protect protruding terminal headers during transit.
Technical FAQ
Can I hot-swap this module while the process is running?
No. Because this unit integrates both high-voltage AC power mains (120/240 VAC) and heavy inductive motor connections on fixed terminal blocks, hot-swapping will cause lethal electrical shock hazards and terminal arcing that destroys internal switching transistors.
How do I program motion profiles without an external PLC?
The unit features an onboard indexer capable of storing programs within its 1792 bytes of NVRAM. You can write and execute motion routines directly using simple single-letter mnemonic codes via a terminal or PC connected to the serial port.
Why is the motor stalling or losing steps at high speeds?
If you are operating in Fixed Resolution Mode with very high step counts (e.g., 51,200 steps/rev), the maximum pulse rate limits shaft rotational speed. Switch to Variable Resolution Mode, which dynamically alters step size on the fly to support high speeds without sacrificing resolution.
Can the 6440-001-K-N drive multiple axes simultaneously?
Yes. It supports a master/slave two-axis configuration. Using the 66 VDC output from terminal J6, you can power and synchronize a secondary compatible slave drive for coordinated multi-axis motion tasks.
