Crystal XP2i-DP Digital Differential Pressure Gauge - Manual (Page 11)

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XP2i Programming Instruction Manual
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eFFectS oF PaSSWord ProtectIon on commandS
If the XP2i is password protected, the following commands will have no effect and return “ X,0 ”:
!_4C , !60F , !68F , !NPK , !PKS , !MSG , !RAS , and !AVS .
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ProGrammInG tIPS
The XP2i is a very straightforward device to communicate with, provided you follow these tips. This advice is derived from our own experiences automating
systems based on the XP2i, as well as the experiences of our users; following these tips will help save you some time.
Anytime you establish (or re-establish) communications with the unit, you should use the following initialization sequence, which will help you deal with
possible noise due to reset, etc.:
1 Reset the unit (unless you must preserve zero, peak values, etc.) by sending the “ !RST ” command.
2 Wait 15 seconds.
3 Read the Bootloader Signature, even if you ignore it, to clear it from the PC’s input buffer; see below for more details.
4 Send a carriage return to clear any noise in the XP2i’s input buffer.
5 An error code, either “ N,Ø ” or “ N,4 ” will be returned; this is normal (you have sent an empty command); read it to clear it. The buffers are now reset.
6 Use the “ ?P,U ” and “ !I,P ” commands to select the pressure unit you want to use.
7 IF APPROPRIATE, zero the XP2i by sending the “ !ZER ” command, since the zero value will be clear.
8 IF APPROPRIATE, clear the high and low peak values to the current pressure (zero, if you followed step 6) by sending the “ !CLR ” command.
9 If you are logging data, you should log the serial number of the unit for traceability purposes by using the “ ?SN# ” command.
You should also log the product code, hardware revision and firmware version with the “ ?VER ” command.
10 Disable automatic shutdown with the “ !NAO ” command.