SECTION 7. MEASUREMENT PROGRAMMING EXAMPLES

10:

0

Offset

04:

P34

Z=X+F

01:1 X Loc TEMP

02: -24

F

03:3 Z Loc [:TEMP COMP]

05:

P37

Z=X*F

01:3 X Loc TEMP COMP

02:-.0698 F

03:3 Z Loc [:TEMP COMP]

06:

P33

Z=X+Y

01:3 X Loc TEMP COMP

02:2 Y Loc PRESSURE

03:2 Z Loc [:PRESSURE ]

07:

P89

If X<=>F

01:5 X Loc CMPILE CK

02:

1

=

03:

0

F

04:

30

Then Do

08:

P34

Z=X+F

01:2 X Loc PRESSURE

02: 47.23 F

03:4 Z Loc [:OFFSET ]

09:

P30

Z=F

01:

1

F

02:0 Exponent of 10

03:5 Z Loc [:CMPILE CK]

10:

P95

End

11:

P35

Z=X-Y

01:4 X Loc OFFSET

02:2 Y Loc PRESSURE

03:6 Z Loc [:DISTANCE ]

12:P End Table 1

7.17PAROSCIENTIFIC "T" SERIES PRESSURE TRANSDUCER

The Paroscientific "T" series transducer has two resonating quartz crystals that output frequency signals for temperature and pressure. The pressure output requires temperature compensation. Instruction 27 measures the outputs and returns period in microseconds (refer to Table 7.17-1).

TABLE 7.17-1 Period Averaging Inst. 27

PARAM.

DATA

 

 

NUMBER

TYPE

DESCRIPTION

01:

2

Repetitions

02:

2

Gain/output option

03:

2

Single Ended Input

 

 

Channel

04:

4

# Cycles to measure

05:

4

Time out (0.01 sec, at

 

 

least the maximum

 

 

duration of the # of cycles

 

 

specified + 1 1/2 cycles.)

06:

4

Destination input location

07:

FP

Multiplier

08:

FP

Offset

 

GAIN/OUTPUT OPTION, PARAMETER 2

The nominal pressure frequency range is 32 to 42 kHz over the stated pressure range (period of 3.1*10-5to 2.4*10-5). The nominal temperature frequency is 172 kHz, ±50 ppm/°C (period of 5.8*10-6). The gain/output option (Parameter 2) is based on the maximum input frequency. For the stated temperature and pressure frequency ranges, the gain codes are 3 and 4 (refer to Table 7.17-2). Codes 1 and 2 are not used with Paroscientific transducers. For period, the output option is 0.

TABLE 7.17-2 Input Frequency Gain Codes

Range

Peak to Peak Volts

Maximum

Code

Required @ Max. Freq.* Frequency

1

2

mV

8

kHz

2

3

mV

20

kHz

3

12

mV

50

kHz

4

2

V

200

kHz

0x Output period in microseconds

1x Output frequency in kHz where x is range code

*AC voltage; must be centered around CR10 ground.

TIME OUT, PARAMETER 5

The "time out", Parameter 5, specifies the maximum length of time the instruction waits on each repetition to receive the number of cycles specified in Parameter 4. The time out units are 0.01 seconds. The minimum time out is the time required to receive the specified number of cycles at the maximum expected frequency.

7-19