Specifications

Section 7. Measurement Instructions
7.9 Peripheral Devices
AM25T (Dest, Reps, Range, AM25TChan, DiffChan, TCType, Tref, ClkPort,
ResPort, ExChan, RevDiff, SettlingTime, Integ, Mult, Offset)
This Instruction controls the AM25T Multiplexer.
Parameter
& Data Type
Enter
Dest Variable
or Array
The Variable in which to store the results of the instruction. When Reps are used the
results are stored in an array with the variable name. An array must be dimensioned
to have elements for all the Reps.
Reps
The number of channels to measure on the AM25T. Enter 0 to just measure
reference temperature.
Range Alpha Code
Voltage Range
Constant mV5000
± 5000 mV
mV1000
± 1000 mV
mV200
± 200 mV
mV50
± 50 mV
mV20
± 20 mV
Autorange
mV2_5 − mV5000
Selects range (Sect. 3.1)
mV200C
± 200 mV The mV200C, mV50C, and mV20C
mV50C
± 50 mV ranges pull the channel into common mode
mV20C
± 20 mV range and check for open circuit
AutorangeC
mV2_5 − mV250
Selects C range
Am25TChan
Constant
The starting input channel on the multiplexer.
DiffChan
Constant
The Differential channel that will be used to make the actual measurements from the
AM25T. If the channel is entered as a negative number, all reps occur on that
channel.
TCType
Constant
The Thermocouple Type Code.
Alpha Code Numeric Type
mV -1 Outputs a voltage, in millivolts
TypeT 0 Copper Constantan
TypeE 1 Chromel Constantan
TypeK 2 Chromel Alumel
TypeJ 3 Iron Constantan
TypeB 4 Platinum Rhodium
TypeR 5 Platinum Rhodium
TypeS 6 Platinum Rhodium
Tref
Variable
The variable in which to store/read the AM25T reference temperature.
ClkPort
Constant
The Digital Output port number that will be used to clock the AM25T. One clock
port may be used with several AM25Ts.
ResPort
Constant
The Digital Output port number that will be used to enable and reset the AM25T.
Each AM25T must have it's own unique Reset line
ExChan
Constant
The Excitation Channel number that will be used to provide excitation for the PRT
reference temperature measurement.
Alpha Code Numeric Description
0 0 Temperature not measured
VX1 1 Excitation channel 1
VX2 2 Excitation channel 2
VX3 3 Excitation channel 3
VX4 4 Excitation channel 4
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