how much time to support?

R

Thread Starter

Rick Roth

Hello All:

In a manufacturing environment covering several production areas with perhaps 50 PLC and HMI systems, what proportion of his time should
a control tech expect to spend on occasional program mods, occasional training of trades persons, supervising upgrades of existing equipment, making the odd network change, and infrequent breakdown help?

The area is fairly static, and my feeling is that one day a week should be plenty.
Is this in the ballpark?

Thanks, and best regards to the List!

Rick
[email protected]
[email protected]
 
J
Sounds like you are in the ballpark. One thing I'd add, though. "Occasional program mods" can be a dangerous thing, sometimes. Too much poking around can lead to problems. Speaking as an OEM,
we have run into many problems which have been created by well-meaning technicians "improving" a working control program.
John Vales
Director of Technology
Wes-Tech Automation, Inc.
[email protected]
 
A

Amr Elaguizy

Hi,
This is a difficult questions to answer for the following reasons:
1. What is your definition of support? Do you mean teaching your personnel how to use and understand PLC as far as the key strokes and how to monitor various inputs ,outputs and flags? Or teaching them the logic behind the program, where they are proficient in the use of PLC's and HMI's?
2. The 50 PLC"s and HMI's are they all the same type and same brand, i.e. all AB, or G.E? or every brand in the world is in your plant?
3. How difficult are the programs?Do they use simple ladder diagram, or are they using files, and indirect addressing? Is the programs in ladder diagram or is it made in Europe using STL, etc....?
Thus my answer is based on the following assumations:
The personnel in the plant are proficient with PLC's and HMI, then you do not need a support personnel, I personally was in various management positions with electricians who really did not need any support, they were very motivated and were considered part of the team and all the production personnel from the machine operator to the production manager asked them for answers, they did all the modification required with the blessing of top management.
On the flip side of the coin, I worked with personnel who only new if an Input or output is on or off by monitoring the led on the PLC input/output board. These needed help all the time and a lot of "spoon feeding". To get guys like that up to speed you probably need a support person for at least a year full time to train them on the simple PLC's key strokes, how to use a PC etc....., and finally the program logic for them to be proficient.
Your question gives me the impression that your personnel will require "spoon feeding" approach, which will probably require a full time support for at least a year, think of it this way 50 programs at 5 days a program of training.Now if the training will be made by the PLC's manufacturer( which will be extremely expensive), and the machine manufacturer as far as the logic, then your estimate of one day might be in the ball park. Finally, if your idea is that the electricians will always be dependant on this
individual? then the next questions is if he will be on call anytime machines are in operation? Which will lead to a dangerous dependency on "one individual know it all", you can not depend on him to be there for ever.
Regards
Amr Elaguizy
 
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Cedillo, Victor B.

I agree however you may want to evaluate case by case. The main factor to evaluate is how well the maintenance diagnostics are presented, HMI/Documentation. If an OEM does a good job in providing iformation needed then I would agree with. I have seen the other scenario which can impact your maintenance time.

Victor Cedillo
Black & Veatch
Configuration Group Manager
*(913) 458-3053
> * [email protected]
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> -----Original Message-----
> From: John Vales [SMTP:[email protected]]
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> Sounds like you are in the ballpark. One thing I'd add, though. "Occasional program mods" can be a dangerous thing, sometimes. ...<clip>
 
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David Lawton Mars

In a message dated 2/1/00,
[email protected] writes:

> Your question gives me the impression that your personnel will require "spoon feeding" approach, which will probably require a full time support for at least a year, think of it this way 50 programs at 5 days a program of training.Now if the training will be made by the PLC's manufacturer( which will be extremely expensive), and the machine manufacturer as far as the logic, then your estimate of one day might be in the ball park. <

Maybe I'm misinterpreting your comments, but I find it hard to believe using a PLC manufacturer and OEM for the training would reduce the learning curve of the personnel involved from 5 days per program to 1 day. I agree that the
trainer needs to be someone that's competent, but this isn;t necessarily the manufacturer of the kit. Also, you might get the best trainer in the world but it really comes down to the aptitude of your personnel to learn the technology. IMHO it's not really necessary to train individuals on every single application program, it's more to do with understanding the structure of PLC code and what they do. I've come across many applications "cold" but if you understand how these systems work and they're documented you can normally work out a program without having any prior knowledge of it.
Regards
David
 
H

Hafeezullah K. Khan

Agree with you John, we have around 70 PLC in our different plants and mostly Seimens and AB but did not face problem since last may be 10 years.
What ever problem appeared to be of software nature had happened due to mishandling and unnecessary poking in the running system. My own experience, the PLC does not give problem but the attitude of working staff with little knowledge always refer as PLC problem even if it is in the field devices.

First thing comes out from user as well as from maint staff is that " please check PLC, there is some problem ". Upon checking 99 % you will find the field input devices have problem.

Khan
 
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Johan Bengtsson

I have got that feeling around here in Swedish industries as well, it is a topic we have been around educating in: basic understaning of the PLC (not the actual programs) and quick troubleshooting in order to:
Instead of calling anyone saying "Hey it stopped working!"
Doing this:
1. Determining the input or output signal where the error occured.
2. Determining the type of problem (sensor, valve, cable, etc.)
3. Call the correct technican for help if needed.
4. Give additional info during the call, ie bring sensor of type XYZ with you, I beleve it is broken. And have a relatively high sucess rate at giving the correct info.

Most problems they had at a particular plant was dirty optical sensors, a problem not actually needing any call once they understood and searched for it.

/Johan Bengtsson

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Geoff Manchester UK

Once you manage to motivate your people, they will want to spend time coming to grips with the system. You can spend all the time and money in the world on structured training, but your people have to do more learning, and you do less teaching, if you get my drift. Furthermore if the people understand the sequence of operations of the system under control, they won't even ned=ed to go near the plc. They will know that a certain valve has filed to open and where the last operative sensor is that should have opened the valve. It's not a question of time and monmey it's about YOUR approach to the staff! Believe me I've been there.
Very best wishes
Geoff
Manchester UK
[email protected]
 
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