Campbell Scientific AM25T 25-Channel Solid State Multiplexer - Manual (Page 20)

AM25T Solid State Multiplexer
Example 4. CR10(X) Program for Measuring 25 Type T Thermocouples with the Differential
Thermocouple Instruction and Long Lead Length Compensation on the RTD Measurement
*Table 1 Program
01: 10
Execution Interval (seconds)
01: Set Port(s) (P20)
;Configure Control Ports for 1 millisecond pulse
1: 9999 C8..C5 = nc/nc/nc/nc
2: 9933 C4..C1 = nc/nc/1ms/1ms
02: Do (P86)
1: 42
Set Port 2 High ;Turn On AM25T
03: Full Bridge (P6)
;Measure the output of the reference temp. full bridge, Vs
1: 1 Reps
2: 23 25 mV 60 Hz Rejection Range ;See Table 6-1 for older AM25T multiplexers
3: 1 DIFF Channel
4: 1 Excite all reps w/Exchan 1
5: 1200 mV Excitation ;See Table 6-1 for older AM25T multiplexers
6: 27 Loc [ Vs ]
7: 1 Mult
8: 0 Offset
04: Do (P86)
;Clock to advance to measure excitation
1: 71 Pulse Port 1
05: Full Bridge (P6)
;Measure the Excitation at the full bridge, Vx
1: 1 Reps
2: 25 2500 mV 60 Hz Rejection Range ;See Table 6-1 for older AM25T multiplexers
3: 1 DIFF Channel
4: 1 Excite all reps w/Exchan 1
5: 1200 mV Excitation ;See Table 6-1 for older AM25T multiplexers
6: 28 Loc [ Vx ]
7: .001 Mult
8: 0 Offset
06: Z=X/Y (P38)
;Calculate Vs/Vx
1: 27 X Loc [ Vs ]
2: 28 Y Loc [ Vx ]
3: 1 Z Loc [ RefTemp_C ]
07: Z=X*F (P37)
1: 1
X Loc [ RefTemp_C ]
2: -0.001 F
3: 1
Z Loc [ RefTemp_C ]
08: Z=X+F (P34)
1: 1
X Loc [ RefTemp_C ]
2: .09707 F
3: 1
Z Loc [ RefTemp_C ]
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