MARK1TIME, MARK2TIME, MARK3TIME and MARK4TIME

Time of mark input event

Platform:

OEM719, OEM729, OEM7500, OEM7600, OEM7700, OEM7720, PwrPak7, SPAN CPT7, SMART2

Firmware Stream:     

This log contains the time of the leading edge of the detected mark input pulse.

  • MARK1TIME is generated when a pulse occurs on a MK1I (EVENT_IN1) input

  • MARK2TIME is generated when a pulse occurs on a MK2I (EVENT_IN2) input

  • MARK3TIME is generated when a pulse occurs on a MK3I (EVENT_IN3) input (OEM7600, OEM7700 and OEM7720 only)

  • MARK4TIME is generated when a pulse occurs on a MK4I (EVENT_IN4) input (OEM7600, OEM7700 and OEM7720 only)

The MARKTIME log (message ID 231) is deprecated. Use the MARK1TIME log as a replacement.

Refer to Technical Specifications for mark input pulse specifications and the location of the mark input pins. The resolution of this measurement is 10 ns.

  1. Use the ONNEW trigger with the MARKxTIME or the MARKxPOS logs.

  2. Only the MARKxPOS logs, MARKxTIME logs and ‘polled’ log types are generated ‘on the fly’ at the exact time of the mark. Synchronous and asynchronous logs output the most recently available data.

  3. ONMARK only applies to MK1I. Events on MK2I (if available) do not trigger logs when ONMARK is used. Use the ONNEW trigger with the MARK1TIME, MARK2TIME, MARKPOS or MARK2POS logs.

  4. Once the 1PPS signal has hit a rising edge, for both MARKxPOS and MARKxTIME logs, a resolution of both measurements is 10 ns. As for the ONMARK trigger for other logs that measure latency, for example RANGE and POSITION logs such as BESTPOS, it takes typically 20-30 ms (50 ms maximum) for the logs to output information from the 1PPS signal. Latency is the time between the reception of the 1PPS pulse and the first byte of the associated log. See also the MARKPOS, MARK2POS, MARK3POS and MARK4POS log.

Message ID:

1130 (MARK1TIME)
616   (MARK2TIME)
1075 (MARK3TIME)
1076 (MARK4TIME)

Log Type: Asynch

Recommended Input:

log mark1timea onnew

ASCII Example:

#MARK1TIMEA,COM1,0,77.5,FINESTEERING,1358,422621.000,02000000,292e,2214;1358,422621.000000500,-1.398163614e-08,7.812745577e-08,-14.000000002,VALID*d8502226

These logs allow you to measure the time when events are occurring in other devices (such as a video recorder). See also the MARKCONTROL command.

GPS reference time is the receiver’s estimate of the true GPS system time. GPS reference time can be found in the header of the log. The relationship between GPS reference time and true GPS system time is:
GPS system time = GPS reference time - offset

Field

Field type

Description

Format

Binary Bytes

Binary Offset

1

MARK1TIME/ MARK2TIME/ MARK3TIME/ MARK4TIME header

Log header. See Messages for more information.

 

H

0

2

week

GPS reference week number

Long

4

H

3

seconds

Seconds into the week as measured from the receiver clock, coincident with the time of electrical closure on the Mark Input port

Double

8

H+4

4

offset

Receiver clock offset, in seconds. A positive offset implies that the receiver clock is ahead of GPS system time. To derive GPS system time, use the following formula:

GPS system time = GPS reference time - (offset)

Where GPS reference time can be obtained from the log header

Double

8

H+12

5

offset std

Standard deviation of receiver clock offset (s)

Double

8

H+20

6

utc offset

This field represents the offset of GPS system time from UTC time (s), computed using almanac parameters. UTC time is GPS reference time plus the current UTC offset minus the receiver clock offset.

UTC time = GPS reference time - offset + UTC offset

0 indicates that UTC time is unknown because there is no almanac available in order to acquire the UTC offset.

Double

8

H+28

7

status

Clock model status, see Table: Clock Model Status

Enum

4

H+36

8

xxxx

32-bit CRC (ASCII and Binary only)

Ulong

4

H+40

9

[CR][LF]

Sentence terminator (ASCII only)

-

-

-