MKS Ophir EA-1, User Manual, Page: 45 / 56

EA-1 User Manual 45
$DP 0 - enables polling until next reset
$DP 1 - disables polling until next reset
$DP 2 - enables polling permanently (responds “0”)
$DP 3 - disables polling permanently (responds “1”)
Note: Factory default is polling enabled; the result of disabling is that if a sensor is swapped over, the software
(firmware and host application) will not be aware of the change and will carry on assuming nothing has happened. If
polling is disabled, the host application will need to take this into account in some way.
BeamTrack Data ($BT):
This command returns data for the Ophir BeamTrack series of sensors which measure Power, Position and Size (PPS).
The data can be returned with a few different formats. For non-PPS sensors, the command returns “?UC”.
The command returns an error code (see details below) and then 3 values for X position, Y position and Size. There
are 3 different modes that are supported, each with a slightly different format to the values returned.
Parameters:
$BT (no parameter): returns “F”, then an error code, then X <value>, Y <value> and S <value> (where S=size), in mm
$BT 1: returns an error code and then X, Y and S data in microns (without the “F”, “X”, “Y”, and “S” as above)
$BT 2: same as no parameter, with more resolution
$BT 3: combination of option 1 and no parameter option
Examples:
$BT (no parameter) -> * F 00040000 X -1.50 Y -0.09 S 33.50
$BT 1 -> * 00040000 -1278 381 33842 [data for
$BT 2 ->* F 00040000 X -1.09833 Y -0.14685 S 37.79891
$BT 3 ->* 00040000 -1998 372 34047 F 00040000 X -2.00 Y 0.37 S 34.05
$BT COMMAND ERROR CODES:
The $BT error code is a bit map where each bit represents some specific error, as below:
Position Codes (bits 0-2 warning, 12-15 error):
0 Warning 0x0000 0001 Position Accuracy Warning (i.e. out of inner circle)
1 Warning 0x0000 0002 Spot Size too large for position measurement
2 Warning 0x0000 0004 Power Low (this might never be used)
12 Error 0x0000 1000 Position not measured (sensor can't measure position)
13 Error 0x0000 2000 Signal too low (i.e. signal is just noise, no meaningful measurements)
14 Error 0x0000 4000 Position Measurement out of range (i.e. out of outer circle)
15 Error 0x0000 8000 General Position Measurement Error
Size Codes (bits 16 warning, 25-31 error):
16 Warning 0x0001 0000 Size Accuracy Warning (i.e. distance from center / diameter > 20%)
17 Warning 0x0002 0000 Spot size less than EEROM limit
18 Warning 0x0004 0000 Spot size greater than EEROM limit
28 Error 0x1000 0000 Size not measured (head can't measure size)
29 Error 0x2000 0000 Negative Discriminant Or/And Negative Size
30 Error 0x4000 0000 Size Accuracy Error (i.e. distance from center / diameter > 33%)
31 Error 0x8000 0000 General Size Measurement Error
Commands for Pyroelectric/PD-C Sensors:
This section lists commands relevant for Pyroelectric and PD-C sensors. Some of the commands described above
are relevant also for the Pyroelectrics/PD-C sensors.
General Energy Commands:
Some of the commands described above in the section “Energy Measurement Commands (Thermopile Sensors)” are
also relevant for Pyroelectrics/PD-C sensors. They allow the user to measure pulses at slow data rates up to ~10Hz.
See details above.