Operator`s manual

SECTION 9. INPUT/OUTPUT INSTRUCTIONS
9-7
TABLE 9-3. Thermocouple Type Codes
Code Thermocouple Type X = 0 Normal Measurement
X1 T (copper - constantan) X = 8 TC input from A5B40 isolation
X2 E (chromel - constantan) (use 5 V range)
X3 K (chromel - alumel) X = 9 Output -99999 if out of common mode
X4 J (iron - constantan) (Inst. 14 only)
TABLE 9-4. Voltage and Temperature Ranges for Thermocouples if Reference Junction is 20
o
C
Voltage Temperature Range
o
C
Range
Type T Type E Type K Type J
±5 mV -131 to 131 -70 to 98 -122 to 141 -84 to 113
±15 mV -270 to 316 -270 to 237 -270 to 386 -210 to 294
±50 mV -270 to 400 -270 to 676 -270 to 1254 -210 to 760
±500 mV -270 to 1000 -270 to 1372
*** 14 THERMOCOUPLE TEMPERATURE, ***
DIFFERENTIAL MEASUREMENT
FUNCTION
This instruction calculates the thermocouple
temperature for the thermocouple type selected.
The instruction specifies a DIFFERENTIAL
VOLTAGE MEASUREMENT (Section 13.2) on
the thermocouple, adds the measured voltage to
the voltage calculated for the reference
temperature relative to 0
o
C, and converts the
combined voltage to temperature in
o
C. The
differential inputs are briefly shorted to ground
prior to making the voltage measurement to
insure that they are within the common mode
range. Table 9-3 gives the thermocouple type
codes for Parameter 4. Select the smallest
voltage range that will accommodate the
temperatures being measured (Table 9-4).
PARAM. DATA
NUMBER TYPE DESCRIPTION
01: 2 Repetitions
02: 2 Range code
03: 2 First TC channel
04: 2 Thermocouple type code
05: 4 Reference temperature
location
06: 4 Destination input location
07: FP Multiplier
08: FP Offset
Input locations altered: 1 for each
thermocouple channel
*** 16 TEMPERATURE FROM ***
PLATINUM R.T.D.
FUNCTION
This instruction uses the result of a previous
RTD bridge measurement to calculate the
temperature according to the DIN 43760
specification adjusted (1980) to conform to the
pending International Electrotechnical
Commission standard. The polynomial range is
-200
o
C to 850
o
C. The error is less than
0.001
o
C between
-100 and +300
o
C, and is less than 0.003
o
C
between -180
o
C and +830
o
C. The error (T
calculated - T standard) is +0.006
o
C at -200
o
C
and -0.006
o
C at +850
o
C. The input must be the
ratio R
s
/R
0
, where R
s
is the RTD resistance and
R
0
the resistance of the RTD at 0
o
C (Sections
7.9 and 7.10).
PARAM. DATA
NUMBER TYPE DESCRIPTION
01: 2 Repetitions
02: 4 Input location of Rs/Ro
03: 4 Input location of result
04: FP Multiplier
05: FP Offset
Input locations altered: 1 for each RTD