Introduction.

Workshop PG5
Instructionlist
Jumps and calls:
We make the difference between jumps and calls. When you want to go from
one point in your block to another point within the same block, then you use a
jump command. If you want to go from one block ( COB, PB, FB, or SB ) to
another block, then you use a call the block.
Another important difference is that if you call a block then the system will
execute the called block and will then return to point where the block was
called from. A jump doesn't return.
WARNING: Jumps are potentially dangerous. This is because you can
end up programming programs with endless loops. Therefore never ever
jump backwards in a program.
Jump instructions
JR Jump relative
JPD Jump direct
JPI Jump indirect
Block calls:
CPB Call program block
CPBI Call program block indirect
CFB Call function block
CSB Call Sequential block
Unconditional
jumps and calls:
If you don't add a condition to your jump or call, then they will be done every
time the program execution arrives to the jump instruction.
COB 0
0
COB 0
0
PB 3
JR
Lablename
CPB 3
CPB 4
PB 4
Lablename:
EPB
EPB
ECOB
ECOB
PG5-07-E © Saia-Burgess Controls Ltd. Page 7-12