Omega Engineering OMB-CHARTSCAN 1400, User Manual

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Appendix A API Commands
ChartScan User’s Manual A-35
H
- Calibrate Channel Offset
TYPE Calibration
EXECUTION Immediate
SYNTAX
Hchan
Calibrate the correction offset constants for given option card where
chan
is
the channel number such that
1
<
chan
<
max
,
where max = 128 for ChartScan/1400. The chassis is
chan = 0
.
DESCRIPTION
Note: This command is only for advanced users who perform their own calibration. It is not necessary for
normal, everyday operation.
Active only in calibration mode, the Calibrate Channel Offset (
H
) command is used to calibrate the correction
offset constants for a given slide-in card. The channel offset values are necessary in order for the internal
firmware to accurately interpret readings coming from the input channels. This command will take the parameter
chan
and calculate the offsets based on the present channel input voltage.
Note: To achieve correct results 0.0 mV must be present at the desired channel prior to performing the
command. The 0.0 mV value is obtained by placing a “short” across the applicable channel. Chapter 6,
Calibration , provides illustrations of various channel shorts.
After the command has been issued, the precision voltage source must remain at its value at least until the
trigger LED stops flashing in order to achieve accurate results. Refer to Chapter 6 for more information
calibration.
EXAMPLE
PRINT#1, “OUTPUT07;K12345X”
‘ Enter Calibration Mode
‘ Connect short across applicable channel
PRINT#1, “OUTPUT07;H17X”
‘ Calculate offsets for T/C card, card #2
‘ Wait for command to complete
‘ Remove precision voltage
PRINT#1, “OUTPUT07;EX”
‘ End Calibration Mode