Programmable Square Wave Out [1204-17]
The Model 1204-17 Square Wave output Option Card provides four programmable square wave outputs for the SecureSync platform.
- Inputs/Outputs: (4) Programmable square wave outputs
- Signal Type and Connector: TTL (BNC)
- Accuracy: ±50 ns (1σ)
- Output Load Impedance: 50 Ω
- Rise Time to 90% of Level: <10 ns
- Programmable Period: 100 ns to 1,000,000,000 ns in 5ns steps, to 60,000,000 µs in 1µs steps
- Programmable Pulse Width: 20 ns to 900 ms with 5 ns resolution
- Maximum Number of Cards: 6
- Ordering Information: 1204-17: Square Wave Out
Model 1204-17 option card rear plate
Configuring a Square Wave Output
To configure one of the Square Wave Outputs:
- Navigate INTERFACES >OUTPUTS: Square Wave Output. The panel on the right side of the screen displays all Sqr. Wv. Outputs and their statuses. All outputs are numbered by signal type (e.g., 'pulse'), hence the numbering may not start with 0.
- Click on the GEAR button to open the Edit window.
The Edit window allows the configuration of the following settings:
Note: The fields viewable are contextually determined according to the Output Mode.
- Output Mode:
- Direct Output Value
- Square Wave
- Output Value: Determines the output level (Low or High).
- Re-Initialize: Re-initializes square wave generation and aligns to 1PPS.
- Signature Control: Controls when the output will be present. See also: Signature Control.
- Edge: Used to determine if the on-time point of the output is the Rising or Falling edge of the signal.
- Offset: Accounts for cable delays and other latencies [nanoseconds].
- On-Time Point Pulse Width: The on-time point pulse width is the pulse width of the first square wave pulse aligned to the 1PPS On-Time Point. This is only active when the alignment count is non-zero [nanoseconds].
- Pulse Width: Pulse width of the output [nanoseconds].
- Alignment Count(s): The alignment counter determines how often (in seconds) the square wave will be aligned back to the 1PPS. Setting zero will disable PPS alignment beyond the initial alignment.
- Time Alignment: (Enabled/Disabled) The time alignment enable changes the function of the alignment counter to align the square wave whenever the current time’s seconds value is a multiple of the alignment count. For example: If time alignment is enabled and alignment count is set to 15 seconds, the square wave will be aligned to the 1PPS when the seconds value on the time display equals 00, 15, 30, 45.
- Period: Sets the period of the square wave (in ns or µs scale).
- The wave’s frequency will display at the top of the window once you have configured the output. The frequency is calculated based on the Period and Period Correction settings.
- Period Correction: Period correction allows for the generation of more precise frequencies at the expense of additional period jitter. An additional clock cycle is added for numerator periods every denominator periods. Over a length of time, the true square wave period comes to:
- Period + (numerator/denominator)] * 5 ns