Campbell Scientific CR10 CR10 Measurement and Control - Page 76

SECTION

6.

g-PIN

SERIAL

INPUT/OUTPUT

9

PrN

t/O

PERTPHERALS

FIGURE

6.2-1.

Hardware Enabled

6.2

ENABLING AND

ADDRESSING

PER|PHERALS

While several peripherals may

be

connected

in

parallel to

the

9-pin port, the CR10 has only one

transmit line (pin 9) and

one

receive line (pin

4,

Table

6.1-1).

The

CR10 selects a peripheral

in

one

of

two

ways:

1)

A specific pin

is

dedicated

to that peripheral and

the

peripheral

is

enabled

when

the

pin goes

high;we

willcallthis

pin-

enabled or simply

enabled.

2)

The

peripheral

is

addressed;the address

is

sent on pin

9,

each

bit being synchronously

clocked

using pin

7.

Pin

6

is

set high while addressing.

6.2.1

PIN.ENABLED

PERIPHERALS

Two

pins are dedicated to specific devices,

Tape

Enable (pin 8) and Modem Enable (pin

5).

Pin

6

(Synchronous Device Enable) can either

be used as

a

Print Enable

OR

it

can

be used

to

address Synchronous Devices (Section 6.6).

Tape

Enable (TE), pin 8, is raised

to

enable

data transfer to

tape.

The

SC92A Cassette

Interface regulates

12

volts from

the

CR10

to

6V

DC

to

power

the

RC35 recorder and also

provides

signalconditioning.

ONLY ONE TAPE

INTERFACE

AND

RECORDER MAY

BE

CONNECTED TO

THE

CR1O.

Modem Enable (ME), pin 5, is raised to enable

a modem

that

has raised

the

ring

line.

Modem/terminal peripherals include Campbell

Scientific phone modems and computers

or

terminals

using

the SC32A

RS232 interface.

The

CR10 interprets

a

ring interrupt (Section

6-2

SYNCHRONOUSLY

ADDRESSED

(sor

cLKlHS)

RF95

AT

BASE

STATION

(SDC

STATE)

KEYBOARD

DISPLAY

STORAGE

MODULE

SDC99

INTERFACE

WITH SDC99

and

Synchronously Addressed Peripherals

6.3) to come

from a

modem

if

the device

raises

the

CR10's Ring line, and holds it high

untilthe

CR10 raises

the

ME

line.

Only one modem/

terminal

may be connected to

the

CR10.

Print Peripherals are defined as peripherals

which have an asynchronous serial

communications port used

to

RECEIVE data

transferred by

the

CR10.

In

most cases

the

print peripheral

is

a

printer, but could also be

an

on-line computer or other device.

Synchronous Device Enable (SDE), pin 6, may

used to enable a print peripheral only

when

no

other addressable peripherals are connected

to

the 9-pin

connector.

Use

of

the

SDE line as

an

enable line maintains CR10 compatibility with

printer-type peripherals

which

require

a

line to

held high (Data

Terminal

Ready)

in

order to

receive data.

lf output

to

both a print peripheral and

an

addressable peripheral is necessary

the

SDC99

Synchronous Device Interface is

required.

With

the

SDC99

the

print peripheral functions as

an

addressable

peripheral.

lf the

SDC99

is not

used, the print peripheral receives

the

address

and data sent to the addressed peripheral.

Synchronous addressing appears as garbage

characters on

a

print peripheral.

6.2.2

ADDRESSED

PERIPHERALS

The CR10 distinguishes itself from

other

Campbell Scientific dataloggers

by

the ability

to

address Synchronous Devices

(SDs).

SDs

from enabled peripherals

in

that

they

are not

enabled solely by

a

hardware line (Section

6.2.1

I

(TE)

TAPE

(ME)

MODEM

(DC112

RF95

sc32A)

(sDE)

PRINT

t-T-'

PIN

ENABLED

Campbell Scientific CR10 CR10 Measurement and Control - Page 76

cLKlHS, sc32A

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