Interface Guide: BD1024 Cesium Atomic Clock

Overview

The BRIDZA BD1024 cesium atomic clock represents the pinnacle of primary frequency standard technology, providing unmatched accuracy and stability for metrology, telecommunications, and defense applications. Available in Standard (BD1024-C) and Professional (BD1024-P) variants, these instruments deliver frequency accuracy of ≤±1E-12 and long-term stability of ≤2.7E-14/100,000s, making them the ultimate reference for precision timing systems.

Supported Models

Model	Frequency Accuracy	Long-term Stability	Typical Application
-------	-------------------	-------------------	---------------------
BD1024-C	≤±1×10⁻¹²	≤8.5×10⁻¹⁴/100k s	Standard metrology
BD1024-P	≤±5×10⁻¹³	≤2.7×10⁻¹⁴/100k s	Primary calibration

Front Panel Layout

 ┌────────────────────────────────────────────────────────────────┐
 │ BRIDZA BD1024 CESIUM ATOMIC CLOCK │
 │ │
 │ ┌──────┐ ┌──────┐ ┌──────┐ ┌──────┐ ┌──────┐ ┌──────┐ │
 │ │ PWR │ │ HT │ │ LOCK │ │ ALM │ │ OCXO │ │ BEAM │ │
 │ │ ● │ │ ○ │ │ ● │ │ ○ │ │ ● │ │ ● │ │
 │ └──────┘ └──────┘ └──────┘ └──────┘ └──────┘ └──────┘ │
 │ │
 │ FREQUENCY OUTPUT PULSE OUTPUT GNSS/EXT │
 │ ┌──────┐ ┌──────┐ ┌──────┐ ┌──────┐ ┌──────┐ │
 │ │10MHz │ │ 5MHz │ │ 1PPS │ │ 1PPS │ │ ANT │ │
 │ │ OUT │ │ OUT │ │ OUT │ │ IN │ │ IN │ │
 │ └──○───┘ └──○───┘ └──○───┘ └──○───┘ └──○───┘ │
 │ │
 │ ┌─────────────────────────────────────────────────────────┐ │
 │ │ RS232/RS485 AC INPUT │ │
 │ │ ┌────┐ ┌────┐ │ │
 │ │ │ DB9│ │ IEC│ │ │
 │ │ └────┘ └────┘ │ │
 │ └─────────────────────────────────────────────────────────┘ │
 │ │
 │ MODEL: BD1024-P S/N: __________ REV: 1.0 │
 └────────────────────────────────────────────────────────────────┘

Interface Definitions

1. 10MHz Frequency Output

Parameter	Specification
-----------	---------------
Connector	BNC female (standard) / SMA (optional)
Impedance	50Ω
Signal Level	13dBm ±2dB
Waveform	Sine wave
Frequency	10.000000MHz
Accuracy	≤±1×10⁻¹² (C) / ≤±5×10⁻¹³ (P)
Harmonics	≤-40dBc
Non-harmonic Spurious	≤-100dBc
Isolation	≥100dBc between outputs

Output Stage:

 ┌─────────────────────────────────────────────────────┐
 │ Internal 10MHz Source │
 │ │
 │ ┌──────┐ Buffer ┌──────┐ Amplifier │
 │ │ Cesium│───────────→│ Gain │──────────────→OUT │
 │ │ Beam │ 10MHz │ 0dB │ +13dBm │
 │ └──────┘ └──────┘ │
 │ │
 │ Output Isolation ≥100dB │
 └─────────────────────────────────────────────────────┘

2. 5MHz Frequency Output

Parameter	Specification
-----------	---------------
Connector	BNC female
Impedance	50Ω
Signal Level	13dBm ±2dB
Waveform	Sine wave
Harmonics	≤-40dBc

3. 1PPS Output

Parameter	Specification
-----------	---------------
Connector	BNC female
Signal Level	NIM / LVTTL (configurable)
Pulse Width	5ms ±0.5ms
Rise Time	≤5ns
Fall Time	≤5ns
Jitter	≤100ps RMS
Polarity	Positive (configurable)
Accuracy	≤±100ns to UTC
Impedance	50Ω (LVTTL) / High-Z (NIM)

Timing Diagram:

 NIM Level: 0V ───────┐ ┌────────────────────
 │ 5ms │
 ──┘ └────
 
 LVTTL Level: 0V ─────────────┐ ┌─────────────
 │ 5ms │
 ──┘ └────
 
 Rising edge @ UTC second

4. External 1PPS Input

Parameter	Specification
-----------	---------------
Connector	BNC female
Signal Level	TTL (3.3V/5V compatible)
Input Impedance	50Ω
Pulse Width	1μs minimum
Max Input Level	±10V (with 50Ω termination)
Purpose	External synchronization reference

5. GNSS Antenna Input (Optional)

Parameter	Specification
-----------	---------------
Connector	SMA female
Frequency	GPS L1 (1575.42MHz) / BeiDou B1
DC Supply	5V @ 100mA (antenna power)
VSWR	≤1.5:1
Cable Loss Compensation	Up to 10dB

6. Serial Monitor Interface

Parameter	Specification
-----------	---------------
Connector	DB9 female
Protocol	RS232 (default) / RS485 (configurable)
Baud Rate	9600
Data Bits	8
Parity	None
Stop Bits	1
Protocol	SCPI-1994

DB9 Pin Assignment:

Pin	RS232 Function	RS485 Function
-----	-----------------	----------------
1	DCD	-
2	TXD	Data+
3	RXD	Data-
4	DTR	-
5	GND	GND
6	DSR	-
7	RTS	-
8	CTS	-
9	RI	-

7. SCPI Command Set

Identification:

*IDN? ; Returns: BRIDZA,BD1024,,,
*OPT? ; Returns installed options

Frequency Control:

:FREQ ; Query output frequency
:FREQ 10000000 ; Set frequency (Hz)
:FREQ:COUP  ; Set coupling (DC/AC)

Output Control:

:OUTP ; Query all outputs
:OUTP:STAT ; Query output status
:OUTP:STAT 1 ; Enable outputs
:OUTP:STAT 0 ; Disable outputs
:OUTP:FREQ ; Query frequency output state
:OUTP:PULS ; Query pulse output state

Status Registers:

:STAT:OPER? ; Operating status
:STAT:OPER:NTR ; Negative transition filter
:STAT:OPER:PTR ; Positive transition filter
:STAT:QUE? ; Error queue
:STAT:QUES? ; Questionable status

Calibration:

:CAL:COUNT? ; Number of calibrations
:CAL:DATE? ; Last calibration date
:CAL:STR? ; Calibration string

Power Supply

AC Input (Standard)

Parameter	Specification
-----------	---------------
Connector	IEC 320 C14 inlet
Voltage	220VAC ±10% (50/60Hz)
Power Consumption	≤50W steady state
Inrush Current	≤30A peak
Protection	EMI filter, surge protector

AC Input Pin Assignment:

 ┌──────────────────┐
 │ ┌──────────┐ │
 1 │ ○ ○ ○ │ L (Live)
 │ │ L N ⏚ │ N (Neutral)
 │ └──────────┘ │ ⏚ (Earth Ground)
 └──────────────────┘

DC Input (Optional)

Parameter	Specification
-----------	---------------
Connector	Military-style circular (4-pin)
Voltage	48VDC ±10%
Current	≤1.5A
Pin 1	+48V
Pin 2	+48V (return)
Pin 3	Signal ground
Pin 4	Not connected

Mechanical Dimensions

4U Rack Mount Chassis

 FRONT VIEW SIDE VIEW
 
 481mm ┌─────────────────┐
 ┌─────────────────────────┐ │ │
 │ │ │ │
 │ │ │ 567mm │
 │ BD1024 │ │ │
 │ 4U │ │ │
 │ HEIGHT │ │ │
 │ (177mm) │ │ │
 │ │ │ │
 │ │ └─────────────────┘
 └─────────────────────────┘
 └──────┘
 400mm
 
 Mounting Holes: 4× M6, slide rails recommended
 Rack Depth: Min 500mm, recommended 600mm

Typical Connection Diagram

 ┌─────────────────────────────────────────────────────────────────┐
 │ SYSTEM CONNECTION EXAMPLE │
 │ │
 │ External Reference Measurement Equipment │
 │ (GPS) │ │
 │ │ │ │
 │ ▼ ▼ │
 │ ┌──────────────┐ ┌─────────────┐ │
 │ │ GNSS Timing │ 10MHz │ Frequency │ │
 │ │ Receiver │─────────────│ Counter │ │
 │ │ │ │ │ │
 │ │ 1PPS ───────│──→ BD1024 └─────────────┘ │
 │ └──────────────┘ │ │
 │ │ │
 │ ┌──────┴──────┐ │
 │ │ 1PPS OUT │ │
 │ └──────┬──────┘ │
 │ │ │
 │ ▼ │
 │ ┌─────────────┐ │
 │ │ Time Interval │ │
 │ │ Counter │ │
 │ └────────────────┘ │
 │ │
 │ Computer/Workstation │
 │ │ │
 │ ▼ │
 │ ┌─────────────────┐ │
 │ │ RS232 │ USB │ │
 │ │ COM │ │ │
 │ └─────────────────┘ │
 │ │
 └─────────────────────────────────────────────────────────────────┘

Status LED Indicators

LED	Color	State	Meaning
-----	-------	-------	---------
PWR	Green	ON	AC power applied
HT	Amber	ON	C-field heating active
HT	Amber	Blink	Warm-up phase
LOCK	Green	ON	Cesium beam locked
LOCK	Green	Blink	Searching for resonance
ALM	Red	ON	Alarm condition
ALM	Red	Blink	Warning condition
OCXO	Green	ON	Internal OCXO active (holdover)
BEAM	Green	ON	Cesium beam enabled

Troubleshooting

Symptom	Cause	Solution
---------	-------	----------
PWR LED off	No AC power	Check power cord and outlet
-	Fuse blown	Replace fuse (2A slow-blow)
HT always on	Warm-up phase	Wait 30 minutes for full warm-up
LOCK flashing	Beam not locked	Allow 30-60 min for initial lock
-	Cesium consumption	Normal for new unit
ALM active	Temperature fault	Check ambient temp (<40°C)
-	Beam current low	Service required
Frequency error	Warm-up incomplete	Allow 24h warm-up for spec compliance
-	External interference	Check for RF interference

Environmental Specifications

Parameter	Specification
-----------	---------------
Operating Temp	+15°C to +40°C
Storage Temp	-40°C to +70°C
Humidity	5% to 90% RH (non-condensing)
Altitude	Up to 3000m operating
Vibration	Refer to datasheet
EMI/EMC	CISPR 11 Class A

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Document Version: 1.0

Last Updated: 2026-05-24

BRIDZA Technologies