Sensoray 518 - Manual (Page 37)

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Calibrate 518
This command calibrates coprocessor internal standards. All measurements made by the
coprocessor are referenced to these standards. To perform a board calibration, you must supply
two reference voltages (5 volts and 500 millivolts) and a reference resistance (380 ohms).
References must be calibrated in the following order: 5 volts, 500 mV, 380 ohms.
select codes for the Calibrate command
COMMAND: (224 + CHAN), (CAL_CODE),(CAL_DATA_MSB), (CAL_DATA_LSB)
RESPONSE: (DON’T_CARE)
Example: This code fragment will assist you in calibrating the 518.
FOR calCode% = 0 TO 2
SELECT CASE calCode%
CASE 0:refName$ = “5 volt”:scalar% = 5000: sensorCode% = 0
CASE 1: refName$ = “500 mV”: scalar% = 50: sensorCode% = 13
CASE 2: refName$ = “380 ohm”:scalar% = 40: sensorCode% = 9
END SELECT
INPUT “What channel is “; refName$; “ reference connected to”; chan%
CALL Send518Byte (16 + chan%) ‘declare channel sensor type
CALL Send518Byte (sensorCode%)
INPUT “What is exact value of “; refName$; “ reference”; actualValue!
CALL Send518Byte (224 + chan%) ‘issue Calibrate command
CALL Send518Byte (calCode%) ‘issue Calibrate command
CALL Send518Byte (actualValue% * scalar%) ‘issue Calibrate command
junk% = Read518Byte% ‘wait for 518 to calibrate
OUT BasePort% + 1, 0 ‘reset 518 board
NEXT calCode%
CAL_CODE FUNCTION
0 5 volt range
1 500 millivolt range
2 400 ohm range