David,
I have seen it this way on account of cable length. Right or wrong, the Site
Planning/Installation section of the Integrators for Allen-Bradley
Controllers document (B0193RG-C on page 52), "For Reliable communicaition,
however, the shorter (20 feet) cable should be used in configurations u
>From our in house AB guru:
" I do not know of a situation in which it wouldn't work at 19.2K, but the
bandwidth requirement is small: the bottleneck is the GP, not the DF1 line. If
he's actually getting real empirical results back showing a huge ==x2
improvement when moving the DF1 connectio
My personal favorite is:
1) Build a DTIME block and set the duration to the time period of
interest * 1.2.
2) Take the 8 most recent "bucket" outputs of the DTIME block to the
inputs of a SSEL block
3) Set the SSEL block to average its inputs.
This approach is kind of cool becau
I have noticed that most of the Allen-Bradley KF2 modules I come across in
the field are running at 9600 baud. I also know of some instances where a
Foxboro Integrator 30 is communicating with AB KF2s at 19.2 Kbaud. Is
there any reason not to run the baud rate at 19.2K? You sure get a lot mor
This may be overly simplistic, but what about using a filter in an AIN block
or an LLAG block? A low pass filter really isn't mathematically the same as
a rolling average, but for a lot of the applications where the process
engineers thought they needed a rolling average, we've found that it's cl
I would use an independent sequence block. Run the block once per minute,
dump the current value of the point to be averaged into a real array indexed
by the minute in the current hour, sum up the values in the array, divide by
60 and you have a rolling hourly average. This will automatically ov
Steve,
CALC blocks are can do something like this, only over less time, or updated
less frequently. You could do a block like this:
PERIOD = 6 (60 sec)
Here's a way to do it using a TIMER and an IND block. You could do without
the timer and just use the WAIT for the period but then you might run into
problems if your CP goes into overrun.
This is set for a flow but will work on anything..
INDEPENDENT_SEQUENCE{**
Hi all,
What I would like is a way to calculate the average position of a valve over
the last hour, updated say every minute.
and then available as an input for a block. Any ideas?
Thanks in advance.
Steve Rigby
Air Liquide Industrie BV
Merseyweg 10
3197 KG Botlek-Rotterdam
The Netherlands
Tel:
