SECTION 9. INPUT/OUTPUT INSTRUCTIONS

 

 

 

 

 

TABLE 9-3. Thermocouple Type Codes

 

 

Code

Thermocouple Type

 

 

 

 

X1

T (copper - constantan)

 

X = 0 Normal Measurement

 

X2

E

(chromel - constantan)

 

X = 8 TC input from A5B40 isolation

X3

K

(chromel - alumel)

 

(uses 5 V range)

 

 

X4

J

(iron - constantan)

 

X = 9 Output -99999 if out of common

 

 

 

 

mode range (Inst. 14 only)

 

TABLE 9-4. Voltage and Temperature Ranges for Thermocouples

 

 

 

 

if the Reference is 20°C

 

 

Voltage

 

 

 

 

 

 

Range

 

Type TType EType KType J

 

±2.5 mV

 

-46 to 50

-21 to 60

-44 to 80

-29 to

67

±7.5 mV

 

-270 to 181

-124 to 134

-270 to 620

-149 to

159

±25 mV

 

-270 to 400

-270 to 365

-270 to 620

-210 to

476

±250 mV

 

−−−

-270 to 1000

-270 to 1372

-210 to

760

PARAM.

DATA

 

NUMBER

TYPE

DESCRIPTION

01:

2

Repetitions

02:

2

Range code (Table 9-4)

03:

2

Single-ended channel

 

 

number for first TC

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

*** 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°C, and converts the combined voltage to temperature in °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. Enter a 9 in front of the

9-8

code and the CR10 will make an additional check on common mode range; -99999 is output for temperature if common mode range is exceeded.

PARAM.

DATA

 

NUMBER

TYPE

DESCRIPTION

01:

2

Repetitions

02:

2

Range code (Table 9-1)

03:

2

Differential channel

 

 

number for first TC

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 International Electrotechnical Commission standard. The range of linearization is -200° to 850°C. The error in the linearization is less than 0.001°C between -100° and +300°C, and is less than 0.003°C between -180° and +830°C. The error (T calculated - T standard)