Campbell Scientific AM25T 25-Channel Solid State Multiplexer - Manual (Page 18)

AM25T Solid State Multiplexer
TABLE 6-3. RTD Excitation Voltage and Measurement Range for AM25T
Multiplexers Prior to Serial Number 1839
Datalogger Temperature Range Excitation voltage Vs Range Vx Range
21X -40 to 85°C
-24 to 65°C 250 mV
350 mV ± 5 mV
± 5 mV ± 500 mV
± 500 mV
CR10(X) -40 to 85°C
-11 to 52°C 350 mV
250 mV ± 7.5 mV
± 2.5 mV ± 2500 mV
± 250 mV
CR7 -40 to 85°C 350 mV ± 15 mV ± 500 mV
6.2.1 Example CR10(X) Programs
The two example CR10(X) programs in this section cover measuring
thermocouples and low level voltage sensors with the differential measurement
instruction. The 21X and CR7 are programmed similarly.
Input locations within the measurement loops must be indexed (--), see
Instruction 87 in the datalogger manual. To index a location, using Edlog ver
6.0 or greater, move the cursor to the Input location label and press “F4”. To
index a location with the datalogger keyboard, press the “C” key when
entering the location number and before the “A” key is pressed.
TABLE 6-4. Wiring for CR10(X) Examples
Function AM25T CR10(X)
+12V Power 12 V 12 V
Power and Shield Ground G
Clock CLK C1
Reset RES C2
RTD Excitation EX E1
Analog Ground AG AG
Common High HI 1H
Common Low LO 1L
Example 3. CR10(X) Program for Measuring 25 Type T Thermocouples or Voltage Sensors
Using a Differential Instruction
*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)
;Turn On AM25T
1: 42 Set Port 2 High
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