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ASCII Time Code In/Out [1204-02, -04]

The ASCII Time Code Option Card, Model 1204-02 (RS-232) provides:

  • one male DB-9 RS-232 input connector (J2),
  • and one female DB-9 RS-232 output connector (J1)

The ASCII Time Code Option Card, Model 1204-04 (RS-485) consists of one RS-485 input, and one RS-485 output, integrated in a shared terminal block connector.

The interfaces accept Asynchronous Serial signals including date and time information. The input and output Data Formats are selected among predefined formats.

ASCII input

The ASCII input provides a serial data interface between an ASCII time generator (e.g., another SecureSync unit), serving as an input reference for Time and 1PPS in order to synchronize SecureSync (in conjunction with, or in lieu of, other available inputs, such as GNSS and/or IRIG).

ASCII output

The ASCII output provides SecureSync with the ability to output one, two or three back-to-back ASCII time code data streams that can be provided to peripheral devices which accept an ASCII RS-232 input data stream for either their external time synchronization or for data processing. See ASCII Time Code Data Formats for a description of all supported time code formats.

The RX signal on an output interface is used for triggering the output ASCII message output when a configured character is received from the peripheral device.

When SecureSync is configured to output only one format message (the second and third formats configured as “None”), the one configured message will be available on the output port as either a broadcast message or only upon a request character being received. SecureSync has the ability to output one or two additional data stream messages immediately following the first message. In this configuration, only the first message determines the on-time point for the entire output string. The on-time points for the second and third messages that are provided at the same time as the first message are discarded. This unique capability allows SecureSync to be able to simultaneously provide multiple pieces of data from different selected format messages.

An example of selecting multiple formats is selecting “NMEA GGA” as the first format, “NMEA RMC” as the second format and “NMEA ZDA” as the third format. Depending on the setting of the “Mode” field (which determines if the data streams are available every second or upon a request character being received), at the next second or the receipt of the next request character, the output port will provide the GGA message followed immediately by the corresponding RMC message for that same second, followed immediately by the corresponding ZDA message for that same second. The first GGA message will provide the on-time point for the entire output data stream.

ASCII Time Code, RS-232 [1204-02]: Specifications

  • Inputs/Outputs: (1) Input, (1) Output
  • Signal Type and Connector:
    • Connector J1 — (RS-232 Output) RS-232 DB-9 F
    • Connector J2 –- (RS-232 Input) RS-232 DB-9 M
  • Accuracy: ±100…1000 µs (format dependent)
  • Maximum Number of Cards: 6
  • Ordering Information: 1204-02: ASCII Time Code Module (RS-232)

Model 1204-02 option card rear plate

Pin Assignments: OUTPUT connector J1

OUTPUT connector J1

Pin-out, OUTPUT connector "J1"

Pin Number Signal Function Notes

Top row of 5 pins

 
1 PPS_OUT 1PPS output TTL level on 50 Ω
2 SERIAL_OUT_TX RS-232 Transmit data Data output (ToD messages)
3 SERIAL_IN_RX RS-232 Receive data Data input into unit; use this to transmit commands to the unit)
4 NC No connection  
5 GND Ground  

Bottom row of 4 pins

 
6 NC No connection  
7 NC No connection  
8 NC No connection  
9 NC No connection  

Pin Assignments: INPUT connector J2

INPUT connector J2

Pin-out, INPUT connector "J2"

Pin Number Signal Function Notes

Top row of 5 pins

 
1 PPS_IN 1PPS input
2 SERIAL_IN_RX RS-232 Receive data Data input into unit; ToD message
3 NC No Connection
4 NC No connection  
5 GND Ground  

Bottom row of 4 pins

 
6 NC No connection  
7 NC No connection  
8 NC No connection  
9 NC No connection  

ASCII Time Code, RS-485 [1204-04]: Specifications

  • Inputs/Outputs: (1) Input, (1) Output
  • Signal Type and Connector: (1) RS-485 terminal block for both Input and Output
  • Accuracy: ±100…1000 µs (format dependent)
  • Maximum Number of Cards: 6
  • Ordering Information: 1204-04 ASCII Time Code Module (RS-485)

Model 1204-04 option card rear plate

Pin Assignments

Pin-out, RS-485 terminal block connector J1

Pin No. Signal Function
1 (left) SERIALTX_RS485+ + RS-485 data output
2 SERIALTX_RS485- - RS-485 data output
3 GND Ground
4 PPS_OUT_RS485+ + 1PPS output
5 PPS_OUT_RS485- - 1PPS output
6 SERIALRX_RS485+ + RS-485 data input
7 SERIALRX_RS485- - RS-485 data input
8 GND Ground
9 PPS_IN_RS485+ + 1PPS input
10 (right) PPS_IN _RS485- - 1PPS input

ASCII Time Code Input: Edit Window

To configure the ASCII Input (also referred to as ‘Reference’), go to its Edit window. For instructions, see: Configuring Option Card Inputs/Outputs.

The Web UI list entries for this card are: ASCII TIMECODE RS-232 and ASCII TIMECODE RS-485.

Note: SecureSync starts numbering I/O ports with 0 (only 1PPS and 10 MHz outputs start at 1, because of the built-in outputs).

The Input Edit window allows the configuration of the following settings:

  • Format Group: Determines the time code message format category (see also ASCII Time Code Data Formats.) Choices are:
    • Auto
    • Spectracom
    • NMEA
    • ICD-153
    • EndRun
  • Format: Once a Format Group has been selected, one or more Format fields may appear, allowing you to select one or more time code Formats. For detailed specifications and limitations on the supported time code formats, see ASCII Time Code Data Formats.

Note: If Auto is chosen as the format group, the format will automatically be Auto-detect. SecureSync will attempt to identify the format of the incoming ASCII message.

  • Offset: Provides the ability to account for ASCII input cable delays or other latencies in the ASCII input. The Offset value is entered and displayed in nanoseconds (ns). The available Offset range is –500 to +500 ms.
  • Timescale: Used to select the time base for the incoming ASCII time code data. The entered Timescale is used by the system to convert the time in the incoming ASCII data stream to UTC time for use by the System Time. The available choices are:
    • UTC: Coordinated Universal Time ("temps universel coordonné"), also referred to as ZULU time
    • TAI: Temps Atomique International
    • GPS: The raw GPS time as transmitted by the GNSS satellites (as of July, 2015, this is 17 seconds ahead of UTC time)
    • A local clock set up through the Time Management Page: This option will appear under the name of the local clock you have set up. Refer to The Time Management Screen for more information on how to configure and read the System Time. Local timescale allows a Local Clock to apply a time offset for Time Zone and DST correction.

      The incoming input time information may be provided as local time, but System Time may be configured as UTC time, so internal computations need to be performed. With the Timescale field set to “Local”, select the name of a previously created Local Clock. The Time Zone and DST rules, as configured in the Local Clock will be applied to the front panel time display. See for more information on Local Clocks.

    Note: The Timescale of the ASCII input (as configured in the ASCII time source) must be set correctly, especially if other input references are enabled. Failure to configure the Timescale of the ASCII input correctly could result in time jumps occurring in the System Time when input reference changes occur. These time jumps could affect NTP and normal operation of the system.

  • PPS Source – choices are:
    • Message: The 1PPS on time point is extracted from the ASCII message received.
    • 1PPS Pin: The origin of the 1PPS on-time-point is the 1PPS input connector.
  • Baud Rate: Determines the speed at which the input port will operate.
  • Data Bits: Defines the number of Data Bits for the input output.
  • Parity: Configures the parity checking of the input port.
  • Stop Bits: Defines the number of Stop Bits for the input port.

ASCII Time Code Output: Edit Window

To configure the ASCII Output, go to its Edit window. For instructions, see: Configuring Option Card Inputs/Outputs.

The Web UI list entries for this card are: ASCII TIMECODE RS-232 and ASCII TIMECODE RS-485.

Note: SecureSync starts numbering I/O ports with 0 (only 1PPS and 10 MHz outputs start at 1, because of the built-in outputs).

The Output Edit window allows the configuration of the following settings:

  • Format Group – configures the message format type. Choices are:
    • None (no message will be output)
    • Spectracom
    • NMEA
    • BBC
    • ICD-153
    • EndRun

    Once selected, the Format Group may offer a choice of Formats. For more information on supported Formats, see ASCII Time Code Data Formats.

    • Format 1: Selects either the first of up to three, or the only format message to be output.
    • Format 2: Selects the second consecutive format message to be outputted. Select “None” if only one output format is desired. “None” will be the only choice available if Format 1 is “None.”
    • Format 3: Selects the third consecutive format message to be outputted. Select “None” if only one output format is desired. “None” will be the only choice available if Format 2 is “None.”
  • Signature Control: Signature Control controls when the selected ASCII data output format will be present; see Signature Control.
  • Output Mode: This field determines when the output data will be provided. The available Mode selections are as follows:
    • Broadcast: The format messages are automatically sent out on authorized condition (Signature control), every second a message is generated in sync with the 1PPS.
    • Request (On-time): A format message is generated in sync with 1PPS after the configured request character has been received.
    • Request (Immediate): A format message is generated as soon as the request character is received. As this selection does not correlate the output data to the on-time point for the message, in Data Formats that do not provide sub-second information (such as Formats 0 and 1 whereas Format 2 provides sub-second information), it should be noted that the output data can be provided immediately, but a time error could occur when using the on-time point of the message in addition to the data for timing applications.
    • Note: The choices available in this field are determined by the choices of Format Group and Format.

  • Time Scale: Used to select the time base for the incoming data. The entered Timescale is used by the system to convert the time in the incoming data stream to UTC time for use by the System Time. The available choices are:
    • UTC: Coordinated Universal Time ("temps universel coordonné"), also referred to as ZULU time
    • TAI: Temps Atomique International
    • GPS: The raw GPS time as transmitted by the GNSS satellites (as of July, 2015, this is currently 17 seconds ahead of UTC time).

    If GPS or TAI time is used, then the proper timescale offsets must be set on the MANAGEMENT/OTHER/Time Management page. (See The Time Management Screen for more information on how to configure and read the System Time). Local timescale allows a Local Clock to apply a time offset for Time Zone and DST correction.

    • A Local Clock can be set up through the Time Management page: This option will appear under the name of the local clock you have set up. See for more information. Local timescale allows a Local Clock to apply a time offset for Time Zone and DST correction.

      The incoming input time information may be provided as local time, but System Time may be configured as UTC time, so internal computations need to be performed. With the Timescale field set to “Local”, select the name of a previously created Local Clock. The Time Zone and DST rules, as configured in the Local Clock will be applied to the front panel time display. See for more information on Local Clocks.

  • Baud Rate: Determines the speed at which the output port will operate.
  • Data Bits: Defines the number of Data Bits for the output port.
  • Parity: Configures the parity checking of the output port.
  • Stop Bits: Defines the number of Stop Bits for the output.

ASCII Time Code Output: Status Window

To view the current settings of the ASCII Output, go to its Status window. For instructions, see: Viewing Input/Output Configuration Settings.

The Web UI list entries for this card are: ASCII TIMECODE RS-232 and ASCII TIMECODE RS-485.

Note: SecureSync starts numbering I/O ports with 0 (only 1PPS and 10 MHz outputs start at 1, because of the built-in outputs).

The Status window displays the following settings:

  • Signature Control: Indicates whether Signature Control is enabled (Signature Control determines when the ASCII data stream will be enabled to be present). See also: Signature Control.
  • Format 1: Indicates the configured format of the ASCII time code input data stream.
  • Format 2: Indicates the configured format of the second consecutive ASCII time code input data stream.
  • Format 3: Indicates the configured format of the third consecutive ASCII time code input data stream.

ASCII Time Code Input: Status Window

To view the current settings of the ASCII Input (also referred to as ‘Reference’), go to its Status window. For instructions, see: Viewing Input/Output Configuration Settings.

The Web UI list entries for this card are: ASCII TIMECODE RS-232 and ASCII TIMECODE RS-485.

Note: SecureSync starts numbering I/O ports with 0 (only 1PPS and 10 MHz outputs start at 1, because of the built-in outputs).

The Status window displays the following settings:

  • Reference ID: Indicates the letters used in the Input Reference Priority table for this particular input reference.
    • Validity: Indicates whether the ASCII input data is present and considered valid for Time and 1PPS references.
      • A green light indicates a valid reference.
      • An orange light indicates the reference is not considered valid.
  • Leap Flag: Displays whether the incoming data stream is indicating that a pending leap second is to be added to the UTC timescale at the end of the month. See Leap Seconds.
  • Format: Indicates the configured format of the ASCII time code input data stream.