Campbell Scientific CR10 CR10 Measurement and Control - Page 29

Parameter

2

is

the

voltage

range

to

use when

making

the measurement.

The

output

of

a

type

T

thermocouple

is

approximately 40

microvolts

per degree C

ditference

in

temperature

between

the two

junctions.

The

t2.5

mV scale will

provide

a

range of

+25OO|4O

=

+62.5

oC

(i.e.,

this scale

will

not overrange

as

long as

the

measuring

junction

is

within 62.5

oC

of

the

panel

temperature). The

resolution

of

the

t2.5

mV range is 0.33 pV or 0.008

oC.

Parameter

3

is

the

analog

input

channel

on

which

to

make the

first,

and

in

this

case

only,

measurement.

Parameter

4

is

the code for the type of

thermocouple

used.

This information

is located

on

the

Prompt Sheet or in the description of

Instruction 14 in Section

9.

The code for

a

type

T

(copper-constantan)

thermocouple is

1.

Parameter

5

is the

lnput

Storage

location

in

which

the

reference

temperature

is stored.

Parameter

6

is

the

Input Storage location

in

which

to

store

the measurement

(or

the first

measurement;

e.9.,

if

there

are

5

repetitions

and the

first

measurement is

stored

in location

3,

the

final

measurement

will

be

stored

in

location

7)"

Parameters 7 and

I

are

the

muttiplier and

offset.

A

multiplier

of

1

and

an

otfset of 0 outputs

the

reading in degrees

C.

A

multiplier

of

1.8

and an otfset of 32 converts

the

reading

to degrees

F.

In

this example,

the sensor

is measured

once

a

minute, and

the

day,

time,

and average

temperature are output every

hour.

Once

a

day

the

day,

time,

maximum

and

minimum

temperatures and the times

they

occur will be

output.

Final Storage data

will

be sent

to

Storage

Module.

Remember, all on-line data output

to

a

peripheral

device

is

accomplished with

Instruction

96

(Sections

4.1

and

12).

The

first

example

described

program entry one

keystroke at

a

time.

This

example does not

show

the

"A"

key.

Remember, "A" is used to

enter and/or advance

(i.e., between

each

line

in

cRl0

ovERvlEw

the

example

below).

This

format

is

similar

to

the

format

used

in

EDLOG.

It's

a good idea

to

have both

the

manual and

the

Prompt Sheet handy when going through this

example.

You can find the

program

instructions

and

parameters on

the

Prompt Sheet and can

read their complete

definitions

in

the

manual.

To

obtain daily output,

the

lf

Time

instruction

is

again

used

to

set the

Output

Flag and

is

followed

by

the

Output

Instructions

to

store time

and

the daily

maximum

and

minimum

temperatures

and the time

each

occurs.

Any

Program

Control

Instruction

which

is used

to set the

Output

Flag high

willset

it low

if

the

conditions

are

not met for

setting

it high.

lnstruction 92 above sets

the Output

Flag high

every

hour.

The Output

Instructions which

follow

do

not output every hour because

they

are

preceded by

another

Instruction

92

which

sets the

Output

Flag high

at

midnight (and sets

it low at any other

time).

This

is

a

unique

leature of

Flag

0.

The

Output Flag'is

set low at

the start of each

table

(Section 3.7).

OV5.3

EDITING

AN

EXISTING PROGRAM

When editing an

existing program

in

the

CR10,

entering

a

new instruction inserts

the

instruction; entering

a

new

parameter

replaces

the

previous value.

To

insert an instruction, enter

the

program table

and advance

to

the

position where

the

instruction

is

to be

inserted (i.e., P

in

the data

portion

of

the

display) key

in

the

instruction

number, and

then

key

A.

The

new instruction

will

be

inserted

at

that

point

in

the table,

advance

through

and enter

the

parameters.

The

instruction that was

at

that

point and all

instructions

following

it

willbe

pushed down to

follow

the

inserted instruction.

An

instruction

is

deleted by advancing to

the

instruction number (P

in

display) and keying #D

(Table 4.2-1\.

To change the value entered

for a

parameter,

advance to

the

parameter and key

in

the

correct

value

then

press

A.

Note that

the

new

value

is

not entered

untilA

is

keYed.

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Campbell Scientific CR10 CR10 Measurement and Control - Page 29

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