Description
The 1756HP-GPS is a GPS-based time synchronization module manufactured by ProSoft Technology under the HiROM product line, designed to mount directly into a standard ControlLogix chassis backplane. It functions as a Stratum 1 NTP server and a Precision Time Protocol (PTP) grandmaster, delivering accurate UTC time to ControlLogix controllers, HMIs, SCADA systems, and other network devices.
With a 75 ns timestamp accuracy for PTP and better than 1 μs accuracy for NTP, the 1756HP-GPS provides a stable, GPS-disciplined time reference that eliminates the drift inherent in standalone system clocks. Its 1PPS (one pulse per second) output, 24-hour holdover capability, and native Studio 5000 integration make it a specialized but essential component for applications where precise event correlation across multiple systems is a requirement rather than a convenience.
Application Scenarios
Consider a regional electric utility operating a transmission substation where protective relays, phasor measurement units, and the control system must all agree on the time of an event to within microseconds. When a fault occurs on the line, the utility needs to know not just that it happened, but exactly when each device saw it—so the protection engineer can reconstruct the sequence of operations, identify the fault location, and determine whether the relay coordination worked as designed.
A ControlLogix controller in the substation, running on its internal clock, will drift by seconds over the course of weeks. That drift makes event logs from different devices impossible to correlate. The 1756HP-GPS solves this by disciplining the controller’s time to GPS with 75 ns PTP accuracy. When the fault recorder, the relay, and the HMI all share the same time source, the event sequence becomes unambiguous. For the utility, this turns a pile of unrelated log files into a single, defensible timeline—the difference between a week of forensic guesswork and a confident root-cause analysis.
Parameter
| Parameter | Value / Description |
|---|---|
| Product Model | ProSoft Technology HiROM 1756HP-GPS |
| Manufacturer | ProSoft Technology (USA), HiROM product line |
| Product Category | GPS Time Synchronization / NTP-PTP Server Module |
| Chassis Compatibility | 1756 ControlLogix chassis (backplane-mounted, single slot) |
| GPS Sensitivity | −160 dBm |
| Time Accuracy (PTP) | 75 ns (timestamp accuracy) |
| Time Accuracy (NTP) | Better than 1 μs |
| Time Source | GPS (UTC), NTP, PTP (IEEE 1588) |
| PPS Output | 1PPS (one pulse per second), 5 V level, 100 μs pulse width, 50 Ω output impedance |
| Holdover Stability | ±25 ppm over 24 hours (factory-calibrated 25 MHz TCXO) |
| Leap Second Correction | Automatic, per IERS bulletin |
| Network Interface | 1 × 10/100 Mbps Ethernet (twisted pair) |
| Serial / Console | 1 × USB (serial console) |
| Antenna Interface | 1 × SMA connector |
| Inputs / Outputs | 1 input, 1 output (1PPS signal) |
| Backplane Current Draw | 320 mA at 5 V DC |
| Power Dissipation | 2.5 W |
| Configuration | Web-based and USB console; no jumpers, no special power supply required |
| Studio 5000 Support | Native (AOP included); compatible with 1756-L8x and 1756-L7x controllers |
| Operating Temperature | 0 °C to +60 °C (32 °F to 140 °F) |
| Storage Temperature | −40 °C to +85 °C |
| Dimensions / Weight | 30 × 132 × 128 mm; 0.125 kg (0.276 lb) |
| Compliance | RoHS 3 (2015/863/EU), China RoHS 2 |
| Warranty | 2 years |