161
ifm Vision Assistant O3M
UK
15.7.6 Example "Event counter" for "RAM write" / "RAM read" modules
In this example, an event counter is implemented for the vertical drilling rig (→ „15.7.1 "Teach" module“).
The "Area not free" events of ROI groups 1-8 of the vertical drilling rig are taken into account. The
transition from "Area free" to "Area not free" (falling edge of the binary signal) is counted.
Description of the modules used in the example:
Module number Module Description
1 RAM read
The state is read from the RAM. Index 0 to 7 is used as address.
The read state corresponds to the values stored in module 6 from the previous
cycle (n-1).
2 AND
If the measurement is valid and in the tolerance range of the reference value, a
"1" is output (area free).
If the measurement is invalid or not in the tolerance range of the reference
value, a "0" is output (area not free).
This corresponds to the behaviour of the vertical drilling rig (→ „15.7.2 Example
for the "Teach" module“)
3 Fixed value The fixed value "1" is defined.
4 DIFF
The difference between the previous and current cycle is established. At the
transition from "Area free" to "Area not free", a "1" is output (falling edge of the
binary signal). In all other cases, a "0" or "-1" is output.
5 Digital output The result of the AND module is output at digital output 1.
6 RAM write
The state of the 8 ROI groups is written to the RAM. Index 0 to 7 is used as
address.
7 RAM read The count of the last cycle is delivered.
8 Equal
If a "1" is present at the inputs, a "1" is output. In all other cases, a "0" is output.
So in the example, a "1" is only output whenever a transition from free (value
="1") to occupied (value ="0") occurs in the areas.
9 ADD The counts of the previous and current cycle are added and output.
10 RAM write The counter reading is saved.
11 Analogue output The count is output at analogue output 0.
To Next Page
Loading...
