Introduction.

Workshop PG5
Instructionlist
Case sensitivity:
Instructions and operands are not case sensitive.
Symbols are not case sensitive unless they contain foreign characters, MotorOn
is the same as MOTORON, but GRÜN is not the same as grün.
Labels are symbol names given to locations in a program (program lines),
which are used as destinations for jump instructions or to provide debug information.
Characters allowed in labels are the same as those of symbols.
Texts are case sensitive. ( Example: TEXT 20
"UART:4800,8,N,1;MODE;MC2;DIAG:F0,R100;" ).
Writing programs
with symbols:
Please make sure you have read the chapter "3. PCD Resources ".
Why should we use symbols and name our input and outputs after all?
Couldn’t we simply write our programs directly using the element address like
shown?
COB 0
0
ACC H
STH I 0
ANH I 4
OUT O 33
ECOB
In fact you could write your programs like this if you like to. But:
First symbols make your program easier to read.
Second, imagine you have a program, which is 4000 lines long. The output O
64 was used 30 times (for exp OUT 0 64, SET 0 64 etc.). During the start-up
of your machine you break the output. For one reason or the other you don't
have a spare card handy but lucky you, the output number O 67 off this card is
available. You decide to use this one instead.
You have changed the address of your output from O 64 to O 67. And you
have to do so 30 times!!!!
Had you declared O 64 by a symbol, you would only have to change the address
one time in the symbol editor.
That’s one of the reasons why its better to use symbols rather then fixed addresses
in your program.
PG5-07-E © Saia-Burgess Controls Ltd. Page 7-6