DI-159 PLC Hardware Manual
StickOS
DI-159 PLC register variables
Variables can also be dimensioned as DI-159 PLC register variables at absolute addresses with
the following statements:
dim
varabs
at address
addr
dim
varabs
as
(
short
|
byte
)
at address
addr
dim
varabs
[
n
]
at address
addr
dim
varabs
[
n
]
as
(
short
|
byte
)
at address
addr
Note that you can trivially crash your DI-159 PLC by accessing registers incorrectly.
Persistent integer (32 bits) flash variables
Variables can also be dimensioned as persistent integer (32 bits) flash variables with the fol-
lowing statements:
dim
varflash
as flash
dim
varflash
[n]
as flash
Persistent flash variables retain their values from one run of a program to another (even if
power is lost between runs), unlike RAM variables which are cleared to 0 at the start of every
run.
Note that since flash memory has a finite life (100,000 writes, typically), rewriting a flash var-
iable should be a rare operation reserved for program configuration changes, etc. To attempt to
enforce this, StickOS delays all flash variable modifications by 0.5 seconds (the same as all
other flash memory updates).
Pin variables
Finally, variables can be dimensioned as pin variables, used to manipulate or examine the state
of DI-159 PLC I/O pins with the following statements:
dim
varpin
as pin
pinname
for
(
digital
|
analog
|
frequency
)
(
input
|
output
)
dim
varpin
[
n
]
as pin
pinname
for
(
digital
|
analog
|
frequency
)
(
input
|
output
)]
These are discussed in detail below, in the sections on
,
, and
.
Examples
>
new
38
Summary of Contents for DI-159
Page 51: ...StickOS DI 159 PLC Hardware Manual 4 is even _ 51...
Page 76: ...DI 159 Block Diagram 76...
Page 77: ...Dimensional Drawing 77...
