Campbell 21X Instrukcja Operatora Pobierz pdf (Strona 79)

redirected tol Final Storage

Area

1,

the time

is

output and t|pe total

is sampled.

I

InRut

Locatijn Labels:

P80

3

2

P72

1

1

P8q

4

4

q

3q

P80

1

2q

P7V,

22Q

08:

P7g

01: 11

02:

2

Pe5

P

Table 1 Programs

Sec. Execution

lnterval

Pulse

Rep

Pulse

Input Chan

Switch

closure

Loc

[:Rain

(mm)]

Mult

Offset

lf time

is

minutes

into a

minute interval

Set

high

Flag 0

(output)

Set

Active Storage

Area

Input

Storage

Area

Array

lD or

location

Totalize

Rep

Loc

Rain

(mm)

lf

X<=>F

X Loc

1Smin tot

F

Then Do

Set

Active

Storage Area

Final Storage

Area

Array

lD or location

RealTime

Day,Hour-Minute

Sample

Rep

Loc

1smin

tot

End

End

Table

1

SECTION 8.

PROCESSING AND

PROGRAM CONTROL

EXAMPLES

1:Rain

(mm)

2:1Smin tot

*1

01: 60

01:

01:

o2'.

03:

o4:

05:

06:

02:

P92

01: 0

02:

15

03: 10

P3

1

1

2

1

es4

0l

8.3 USING CONTROL

PORTS AND

LOOP TO RUN

AM416

MULTIPLEXER

This example uses an

AM416 to measure

16

copper-constantan

thermocouples

and

16 Model

223 soil moisture blocks.

The sensors are

read

every

ten

minutes and

the average

value output

once

an

hour. The

multiplexer

is housed in an

AM-ENCT enclosure

to minimize thermocouple

errors created

by thermal

gradients.

Thermocouple Wire

is run from the 21X to

the

AM416

common

used

for the

TC

measurements

and the 21X

panel

temperature

is

used

for the

reference

temperatu

re.

The AM416 switches

lhe 223

moisture

block

out

of the

circuit

when

it is not

being measured.

This eliminates the

need for the

blocking

capacitors used

in the

model

227

soil moisture

block. The

223 blocks are

about

one

fifth the

cost of lhe 227 blocks.

Control

ports

are used

to

reset the

AM416

and

clock it through

its channels.

The

sequence

of

the

program

is:

Measure

the 21X

panel

temperature

for TC temperature

reference.

21X

sets the

port

high which resets the

AM416.

A loop

is entered;

within each

pass:

The

port

clocking

the

AM416

is

pulsed.

The connected

TCs and moisture

blocks

are

measured.

21X sets

the

port

controlling

AM416

reset

low.

Soil

moisture

measurements are

converted

to block

resistances.

The input location

in which the temperature

and

soil moisture

measurements

are stored

is

indexed

to the

loop counter

(lnstruction

87,

Section 12). An

indexed

location is incremented

by one with each

pass

through the

loop.

For

example, on

the first

pass

temperature

is stored

in Location 2, and

soil moisture in

Location

18.

On

the

second

pass

temperature is stored

in

Location

3,

and soil

moisture

in

Location

18.

After 16 loop

passes,

temperature

and

soil

moisture measurements

occupy

Locations

2

through

17

and

18 through

33, respectively.

Connections are shown

in Figure

8.3-1.

03:

01:

02:

04:

01:

02:

05:

01:

02:

03:

o4:

06:

01:

02:

07:

01:

09:

10:

8-3

1 2 ... 74 75 76 77 78 79 80 81 82 83 84 ... 190 191

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