Interface Guide: STZ-MS Series Phase Micro-Stepper

Overview

The BRIDZA STZ-MS series phase micro-stepper enables ultra-fine adjustment of clock signals with phase resolution of 2π/2³² (approximately 0.024 femtoseconds). This precision allows clock synchronization at the highest level required by VLBI, radio telescope arrays, and advanced metrology applications.

Supported Models

Front Panel Layout

 ┌────────────────────────────────────────────────────────────────┐
 │ BRIDZA STZ-MS2 PHASE MICRO-STEPPER │
 │ │
 │ ┌──────┐ ┌──────┐ ┌──────┐ ┌──────┐ │
 │ │ PWR │ │ LOCK │ │ SYNC │ │ ERR │ │
 │ │ ● │ │ ● │ │ ● │ │ ○ │ │
 │ └──────┘ └──────┘ └──────┘ └──────┘ │
 │ │
 │ INPUT OUTPUT │
 │ ┌────────┐ ┌────────┐ │
 │ │ 10MHz │ │ 10MHz │ │
 │ │ IN │ │ OUT │ │
 │ └──○─────┘ └──○─────┘ │
 │ │
 │ ┌──────────────────────────────────────────────────────────┐ │
 │ │ ETHERNET RS232 DC INPUT │ │
 │ │ ┌────┐ ┌────┐ ┌────┐ │ │
 │ │ │RJ45│ │DB9 │ │ ○- │ │ │
 │ │ └────┘ └────┘ └────┘ │ │
 │ └──────────────────────────────────────────────────────────┘ │
 │ │
 │ DISPLAY: PHASE = +123.456 fs FREQ = +1.23E-15 │
 └────────────────────────────────────────────────────────────────┘

Interface Definitions

1. Reference Input (10MHz)

2. Frequency Output (10MHz)

3. Control Interface (RS232)

4. Ethernet Interface (Optional)

SCPI Command Set

Identification

*IDN? ; Returns: BRIDZA,STZ-MS,,
*OPT? ; Returns installed options
*RST ; Reset to defaults
*CLS ; Clear status

Phase Control

:FREQ:PHAS? ; Query current phase (ps)
:FREQ:PHAS  ; Set phase offset (ps)
:FREQ:PHAS:REL  ; Set relative phase step
:FREQ:PHAS:REF ; Set current phase as reference
:FREQ:PHAS:RESET ; Reset phase offset to zero

:STEPh? ; Query phase step size
:STEPh  ; Set phase step (fs)

Frequency Micro-Step

:FREQ? ; Query frequency
:FREQ  ; Set frequency (Hz)
:FREQ:COEF? ; Query frequency coefficient
:FREQ:COEF  ; Set frequency coefficient (1E-9)

Output Control

:OUTP:STAT? ; Query output status
:OUTP:STAT 1 ; Enable output
:OUTP:STAT 0 ; Disable output
:OUTP:GAIN? ; Query output gain
:OUTP:GAIN  ; Set output gain (dB)

Status

:STAT:OPER? ; Query operating status
:STAT:QUE? ; Query error queue
:SYST:ERR? ; Query system error
:SYST:TEMP? ; Query internal temperature
:SYST:LOCK? ; Query PLL lock status

Phase Adjustment Resolution

The phase micro-stepper provides unprecedented resolution:

Calculation:

Phase step = 1 cycle / 2³²
 = 100ns / 2³²
 = 100,000,000 fs / 4,294,967,296
 = 0.023283 fs

Power Supply

Typical Application

 ┌────────────────────────────────────────────────────────────────┐
 │ VLBI CORRELATOR SYSTEM │
 │ │
 │ Antenna 1 Antenna 2 │
 │ ┌─────────┐ ┌─────────┐ │
 │ │ H-Maser │ │ H-Maser │ │
 │ └────┬────┘ └────┬────┘ │
 │ │ │ │
 │ └──────────┬───────────────────────┘ │
 │ │ │
 │ ▼ │
 │ ┌──────────────┐ │
 │ │ STZ-MS2 │ │
 │ │ Phase Micro │ │
 │ │ Stepper │ │
 │ └──────┬───────┘ │
 │ │ │
 │ ▼ │
 │ ┌──────────────┐ │
 │ │ VLBI │ │
 │ │ Correlator │ │
 │ └──────────────┘ │
 │ │
 │ Phase adjustment: ±0.024fs resolution │
 │ │
 └────────────────────────────────────────────────────────────────┘

Python Control Example

import serial

class PhaseMicroStepper:
 def __init__(self, port='/dev/ttyUSB0', baudrate=9600):
 self.ser = serial.Serial(port, baudrate, timeout=1)
 
 def send_command(self, cmd):
 self.ser.write(f"{cmd}
".encode())
 return self.ser.readline().decode().strip()
 
 def get_id(self):
 return self.send_command("*IDN?")
 
 def set_phase(self, phase_ps):
 """Set phase offset in picoseconds"""
 return self.send_command(f":FREQ:PHAS {phase_ps}")
 
 def get_phase(self):
 """Get current phase offset"""
 return float(self.send_command(":FREQ:PHAS?"))
 
 def set_step(self, step_fs):
 """Set phase step in femtoseconds"""
 return self.send_command(f":STEPh {step_fs}")
 
 def reset(self):
 """Reset phase to zero"""
 return self.send_command(":FREQ:PHAS:RESET")
 
 def close(self):
 self.ser.close()

# Usage
pm = PhaseMicroStepper('/dev/ttyUSB0')
print(pm.get_id())

# Step phase by 10fs
current = pm.get_phase()
pm.set_phase(current + 10)
print(f"New phase: {pm.get_phase()} ps")

pm.close()

Troubleshooting

Download Resources

• STZ-MS Datasheet
• SCPI Programming Guide

Document Version: 1.0

Last Updated: 2026-05-24

BRIDZA Technologies