Laser Technology, Inc. TruPulse 200 User's Manual 6
th
Edition
Page 28
Optional Remote Trigger
It is possible to remotely trigger the TruPulse and take a measurement by using an external
computer, data collector, or switch closure. Remote triggering is accomplished by providing an open
collector closure to ground or an active low TTL or RS232 level signal to the 'trigger' pin on the
serial connector. This option requires a special order download cable that connects the remote trigger
signal from the TruPulse to the 'RTS' output signal of a computer's serial port.
When using a serial cable with a remote trigger connection, care must be taken in controlling the
state of the RTS signal from the host computer. Often times the default state of the RTS signal will
be low, causing an inadvertent trigger of the TruPulse. Since the remote trigger signal is treated the
same as a button press on the TruPulse, holding the signal low is identical to holding down a button,
which prevents a response to any additional keys that are pressed.
Download Message Format
The CR400 data format follows the guidelines of the NMEA Standard for interfacing Marine
Electronic Navigational Devices, Revision 2.0.
NMEA 0183 provides for both standard and proprietary data formats. Since none of the standard
formats are useful for the data transferred from the TruPulse, special proprietary formats are used.
Rules described in the NMEA standard governing general message structure, leading and trailing
characters, numeric values, delimiting character, checksums, maximum line length, data rate, and bit
format are followed exactly. As required by NMEA 0183, the CR400-format does not respond to
unrecognized header formats, malformed messages, or messages with invalid checksums.
Summary of Contents for TruPulse 200
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