Support
10
XP2i Programming Instruction Manual
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BootLoader SIGnature
A quick note about the Bootloader Signature: This string contains a 19 character, product-specific string (whose contents may vary with product revision),
followed by a carriage return (CR), making the total string length 20 bytes. However, a reset turns the RS-232 interface on and off, so it may be subject to
noise; a
NULL
may be received before the signature is sent, and the first character or so of the Bootloader Signature may be corrupted. A framing error is
also possible. The procedure above will deal with this situation properly. Should you want to parse the bootloader signature, it has the following format:
“
=xxxxxxxxxxxxxxxxx=”
where
x
will vary with product revision. The bootloader signature is used by the firmware upgrade tool, but should NOT be
used to identify the firmware version; use the “
?VER
” command for that purpose. If you have a system that may have Crystal DTG or XP2i units attached, you
can use this signature to determine which device is in use.
Note:
Any time you detect the Bootloader Signature, the unit has been reset, or disconnected from and reconnected to power; turning the unit on and off
with the button will not send the Bootloader Signature. You can use this behavior to detect a battery change, or a problem with the XP2i.
Some commands may take up to 500 milliseconds to return a reply. You should always wait at least 50 milliseconds after each reply is received before sending
the next command. After a reset command it may take up to 15 seconds before the gauge resumes normal operation.
Data transmitted from the XP2i will always be 7-bit ASCII. Any high-ASCII characters indicate a line-noise problem, or a problem with the XP2i or PC.
The XP2i has very thorough integrity checks to catch corruption of program or calibration data memory. Should the data memory integrity check fail, the unit
displays “
ERR 1
” on the display as the value line of the serial output. It is important to check for this, or you may mis-parse that line as “1 PSI”, depending on
your program. Should the program memory integrity check fail, the unit will continuously reset, blinking the LCD on and off, and the serial output will alter-
nate between the bootloader signature and a line reading “
CRC FAIL
”. This condition can be recovered from in the field by reloading the unit’s firmware;
contact technical support for details.
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contact uS
Phone
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Toll-Free
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Fax
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Web
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crystalengineering.net
If calling, have ready the model number, serial number, date of purchase, and reason for return. You will receive instructions for returning the device to us.
