u/Hann_33

To my fellow rung straddlers.

Does anyone actually understand S88?
I have been playing with batch processes for a while now and I am trying to level up my game.

For those who are neck deep:

1. Is this a skill and understanding worth having?

2. Is there a legitimate value add on the engineering side, structuring code to comply with this standard, Or just boiler plate that doesn't get used.

3. Are there any accreditations that allow you to brag for money to your clients that your site is compliant.

4. Why do this

5. How do I learn to do this, we use Omron so I will need to apply the principles into code that I can run on an omron sysmac PLC.

Background:

On our site, we have function blocks that control our equipment e.g. a valve or (Equipment Module) as I am now learning. And we have Sequences (or Phases if you will) that allow me to do some task like heat a vessel.

Presently the operators click, fill, heat, cool, on the CIP as things finish, there is nothing that sits above the sequence level.

Share your wisdom with a rooky :)

Hi Team,

When you are creating your beautiful millennial grey HMIs. What HEX codes do you use and how do you separate out the different

E.g.
Main Menu
Disabled
Device Off
Outlines
Font backgrounds

How many different greys do you use and how do you organise them for a nice ISA 101 compliant HMI

Here is the problem.
I have three vessels that can all transfer to each other.
They all have levels and I would like to track the transfers in a database when they happen.

I am trying to figure out what the best practice is for doing this.

e.g. Example 1 (6 Sequences)
T1->T2,T3 (2 Sequences)
T2->T1,T3 (2 Sequences)
T3->T1,T2 (2 Sequences)

Example 2 (3 Sequences)

T1->Tx (1 Sequence with a T2,T3 selection)
T2->Tx (1 Sequence with a T1,T3 selection)
T3->Tx (1 Sequence with a T1,T2 selection)

Example 3 (1 Sequence)

Tx->Tx (any to any, source selection and destination selection)

Each example introduces more complexity since you will have to decide what valves to open based on selections. And the routes that may need to be opened could also vary in complexity. and I am also trying to figure out if there is a point of scale where one option becomes better than others, e.g. 20 vessels.

What architecture can I consider implementing, and what is the best solution.

Thanks

I have been doing this long enough now where I am in the "too scared to ask" camp.

In the context of a sequence that does something e.g. fills a tank with water.

Permissive: is the tank empty/are you resuming from an interrupted fill

->Disables start button if not true

Interlock: the pump has a fault on it

->Disables start button if true

->If the sequence is running stop

Fault:
a critical process condition that has gone wrong, stops sequence

-> High level sensor is triggered

Alarm:
a non-critical process condition, does not stop sequence

Filling is taking a long time but I don't want to stop, just alert the situation to someone

It seems to me that a fault condition should also exist as a permissive, e.g. you faulted on high level, you can start because you are at high level.

Both a fault an alarm will end up in a log.
What do you do with an interlock?

I normally add an alarm to alert if a sequence has not ended correctly, but then you still have to do some investigation to match oh the thing faulted then my sequence stopped.

What I have done in the past is treated interlocks only as thing the inhibit a start, and used faults as something that stops, not using permissives and alarms, in the context of a sequence.

Can someone smarter give me some insight in how to think about these 4 buzz words

Hi Team,

Has anyone out there worked on the LINAK LA25 Linear Actuators?
I have got the device talking to the PLC and I am able to get it moving.

Every time I download to the PLC or cycle it to program mode, I get an over current fault.
I suspect it is because the output command is reset then some inconsistent data is being sent to the actuator. I am able to clear the fault, but I would rather avoid having it occur every time I download to the PLC.

Has anyone worked with these before or have access to a function block they are willing to share?

https://preview.redd.it/71e8aqc7p3ah1.png?width=605&format=png&auto=webp&s=0a3e1cf5ea27f8c8532c933f6063dcc7c7c5d7e8

Thanks

Got caught by a trap, for your benefit here is what I learned.

When using P Only control here is the equation that the controller uses

Output = 50% + P*(SP-PV) + Manual Offset
(Not easily found in any documentation, has to be inferred)

If you are using P Only control because you are using it to heat a vessel and don't want it to overshoot, then you have to set the manual offset (MR) to -50%

SR90F-1JE Instruction Manual

Hopefully this saves someone a couple of hours of wondering why the PV > SP and the output is half open...