Remote-processing RPC-2350 Manuale Utente Scaricare il pdf (Pagina 13)

CHAPTER 2 SETUP AND OPERATION

2-7

You can wr ite a program in lower case characters.

CAMBASIC translates them to upper case.

Some program mers put "N EW" as the first line in the

file. During debugging, it is common to insert

"temporary" lines. Adding NEW ensures that these lines

are gone. D ownloading time is incr eased when the old

program is still pre sent.

Instead of uploading and downloading programs, you can

save them to the on card Flash E PRO M. This is useful if

you are using a terminal to write programs. Make sure

the 'Autorun' jumper is installed (See Chapter 3

SAVING PROGRAMS). To prevent automatic program

execution on power up, insert the STOP statement at the

beginning of the program (such as line 1). When you

power up the RP C-2350 , the progr am is transferr ed into

RAM and executed. Delete the program line with the

STOP statement to norm ally start programs.

Writing with line numbers

You can manually enter line nu mbers. T he problem is

when you have to add another line. It is quite common

for programs to grow and run out of line numbers. You

can execute the RERUM command to renumber lines.

A technique used to further program documentation and

reduce code space is the use of comments in a

downloaded file. For example, you could have the

following in a file written on your editor:

'Check VAT temperature

'Read the output from the RTD and

' calculate the temperature

2200 a = ain(0) :'Get temp

The first 3 comments downloaded to the RPC -2350

are ignored. Similarly, the empty lines between

comm ents are a lso ignored . Line 2200, with its

comment, is a part of the program and could be listed.

The major pena lty by wr iting a progr am this way is

increased download time.

NOTE: Some ve rsions of P C Sm artLin k may op tionally

strip comments before downloading. Check

your manual to see if this option is available.

If you like to write programs in separate modules, you

can download them separately. Modules are assigned

blocks of line numbers. Start up code might be from 1

to 999. Interrupt handling (keypad, serial ports) might

be from lines 1000 to 1499. Display output might be

from 1500 to 2500. The program mer m ust determine

the number of lines required for each section.

When replacing a program or section, downloading time

is increased. Blocks of line numbers cannot be

renumbered by CAMBASIC when other par ts of the

program are installed. However , if a particular section

is the only program downloaded, then line renumbering

in that range is possible. Refer to the CAMBASIC

RENU M comm and.

CAM BASIC automatically formats a line for minimum

code space and increased readability. For example, you

could download the following line of code:

10 fora=0to5

When you listed this line, it would appear as:

10 FOR A = 0 TO 5

Spaces are initially displayed but not stored. The

following line:

10 for a = 0 to 5

would be compressed and displayed as in the second

example above. Spaces are removed.

Writing without line numbers

Many programming languages such as C and versions of

BASIC and do not use line numbers. CAMBASIC uses

line numbers simply because you can edit them through a

serial terminal.

You can write and edit CAM BASIC programs without

using line numbers. This makes for m uch mor e readable

code.

The demo program NOLINES.BAS is such a program.

(Other program demos may also not use line numbers.)

The key is to use the AUTO com mand. This command

automatically assigns a num ber to eac h progr am line as it

is entered.

There are a few things you have to keep in mind.

1. Put the NEW statement at the start of the

program file. This removes old code.

2. You must use the remark statement (') in lines

that do not have any code. This is because AUTO

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Remote-processing RPC-2350 Manuale Utente Pagina 13

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