Plc suggestion

aec

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Join Date
Sep 2011
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dubai
Posts
162
PLC REQUIREMENTS:

i. PLC shall be designed, constructed & tested in accordance with IEC 61131.

ii. PLC shall have self diagnostic feature, to detect failure. When a failure happens it should raise alarm.

iii. Failed modules within the PLC system shall automatically detected, identified and alarmed via output contact(s), diagnostic status words & LEDs without interruption of normal processing functions. On-Line removal/replacement of any PLC system module shall be possible without having reconfigure system software, alter system wiring or cabling, or re-initialize the PLC system.

iv. The PLC shall support PID closed loop control, open loop control, and logic & sequence functions.

v. The PLC shall support Report-By-Exception and Report-All status data.

vi. The PLC shall automatically upload data to the Master station upon receiving a poll request.

vii. The PLC shall support remote configuration, remote down loading, remote uploading of stored data, and remote data base modifications.

viii. The PLC shall be capable of being rebooted via a remote SCADA signal.

ix. The PLC Mean Time between Failures (MTBF) shall not be less than 20,000 hours. This is applicable to the full complement of hardware comprising the PLC.

x. It shall be possible to configure the same PLC to function as: a) Unit PLC Station (slave to a master).

2. CPU:

CPU shall be redundant.


When PLC failure occurs, the discrete outputs shall freeze to its current state or turn off.

3. I/O DETAILS:

Digital ip – 31
Digital op – 7


A failure or fault indication on any I/O module shall initiate a system status alarm.

Discrete outputs that drive solid state inputs, i.e annunciator points, shall be provided with dry relay contacts.

Digital O/P modules shall be 120VAC


4. POWER SUPPLIES:

i. Incoming Power source to the PLC system will be 120VAC

ii. Power fail detection & recovery.

5. COMMUNICATION:

i. Two (2) 10/100 Ethernet communication ports with RJ-45 connector.

ii. Isolation: Ethernet port isolated to 500Vdc

iii. One (1) RS-232 & One(1) RS-485 serial communication port.

iv. The PLC shall be capable of operating in a stand-alone manner, with full functionality, independent of communication with the Master station.

v. In case of a communication failure with the master, the PLC shall be capable of archiving data points. The number of points shall be specified in the PLC Specific Requirement Sheet.

vi. Upon recovery from communication or power failure, the PLC shall be ready to accept automatic download of database changes from the master station and also it shall be ready to respond to a poll request within 30 seconds of re-establishing communication.
6. Environmental Conditions:

Operating Temperature range: 10° to 70°C ,
Relative Humidity:15-95% non-condensing

Please suggest me a PLC .
 
Analyzing all of these requirements and matching the different PLC brands/types will take me about two weeks. What are you willing to pay me for that?

Kind regards,
 
Analyzing all of these requirements and matching the different PLC brands/types will take me about two weeks. What are you willing to pay me for that?

Kind regards,

Hi jvdcande ,

Sorry , I have just done two projects and those project I selected PLC based on the number of inputs and outputs . Now this list was given to me by my boss and asked me to suggest a PLC .
He very well knows I am fresh in this field but unfortunately he too does not know much about PLC .

So being experience in this field please help me like :

how to select a PLC ? should I have to ask the PLC vendor by stating this points ??

Or should I have to inform my boss ??

I am afraid to do mistake as it will lead to a big mess ?

Kindly advice. I have been browsing but couldnt find a right direction due to lack of experience and more over there are no seniors or anyone who knows about PLC in my company .So from the begining I am learning from this forum .

Thanks for your response . And advance thanks for your advice , suggestion , help .
 
From a quick read of the spec I would think you need some type of rtu type device. Something like Scadapak from Control Microsystems (now part of Schneider) would probably fit
http://www.controlmicrosystems.com/

but they just need us to provide a PLC which can be rebooted from remote scada which they will be having . I mean scada or RTU is not provided by us . Only PLC is to be selected which can connect to their remote device.
 
Personally I think it is best to ask different manufacturers to make an offer based on this requirements. Their salespeople are paid to do that, and they only have to analyze their own brand to see which model fits the requirements.

Kind regards,
 
Hi AEC - dont you think it is unfair to ask us to chase this type PLC for you. After we have you get paid for it - don't you.

You need to contact your suppliers with the written SPEC you have.
most of us have to do exactly the same thing.
Jean Pierre has offered to assist you at a cost - If you don't want to attempt to contact suppliers yourself then organise to pay him.
 
Thank you all for your time and response .

all I needed was just a suggestion or a advice what I have got in the above post . Now I will go to my boss and ask him to contact different manufactures .

This is my first experience .

Really I just had to get some advice from experienced people like you so that I can proceed , I didnt mean you people to do my work .

I just wanted to know how people working in this feild would select a PLC so that I can follow the same.

Again I thank you all for ur time and response .
 
Last edited:
This kind of spec drives me insane! We see it all the time on municipal projects in the US. Sometimes it is cutting and pasting one manufacturer's suggested specs, and sometimes it is an engineer taking the features he likes from many different PLC brands and creating a spec for something no one makes.

In addition to contacting suppliers as indicated above, I suggest you contact the potential customer and ask him if he has a brand preference and if he had a specific PLC in mind when he created this spec. You may have to submit a request for information in writing, and the engineer may not give you an answer, but it costs nothing to try. More times than not when I did this the engineer was glad someone cared enough to ask his opiniion.
 
People who work in this field would normally write a specification of requirements as you have already given into a tender document and then issue it for tenders to a list of suppliers whom you would have done some basic research on to more or less establish that they could meet your specification. This would give you a shortened list of possible suppliers.
You would then have to go through a tender evaluation to ensure that you will get something which meets your specification, budget and project schedule for delivery etc. The more tenders you issue the more work you have to do to evaluate the tenders.
So it is better to come up with a preferred list to tender of say 3 to 5 suppliers. See the link below for possible suppliers which is considerable.

http://www.plcs.net/chapters/links.htm
 
PLC REQUIREMENTS:

i. PLC shall be designed, constructed & tested in accordance with IEC 61131.

ii. PLC shall have self diagnostic feature, to detect failure. When a failure happens it should raise alarm.

iii. Failed modules within the PLC system shall automatically detected, identified and alarmed via output contact(s), diagnostic status words & LEDs without interruption of normal processing functions. On-Line removal/replacement of any PLC system module shall be possible without having reconfigure system software, alter system wiring or cabling, or re-initialize the PLC system.

iv. The PLC shall support PID closed loop control, open loop control, and logic & sequence functions.

v. The PLC shall support Report-By-Exception and Report-All status data.

vi. The PLC shall automatically upload data to the Master station upon receiving a poll request.

vii. The PLC shall support remote configuration, remote down loading, remote uploading of stored data, and remote data base modifications.

viii. The PLC shall be capable of being rebooted via a remote SCADA signal.

ix. The PLC Mean Time between Failures (MTBF) shall not be less than 20,000 hours. This is applicable to the full complement of hardware comprising the PLC.

x. It shall be possible to configure the same PLC to function as: a) Unit PLC Station (slave to a master).

2. CPU:

CPU shall be redundant.


When PLC failure occurs, the discrete outputs shall freeze to its current state or turn off.

3. I/O DETAILS:

Digital ip – 31
Digital op – 7


A failure or fault indication on any I/O module shall initiate a system status alarm.

Discrete outputs that drive solid state inputs, i.e annunciator points, shall be provided with dry relay contacts.

Digital O/P modules shall be 120VAC


4. POWER SUPPLIES:

i. Incoming Power source to the PLC system will be 120VAC

ii. Power fail detection & recovery.

5. COMMUNICATION:

i. Two (2) 10/100 Ethernet communication ports with RJ-45 connector.

ii. Isolation: Ethernet port isolated to 500Vdc

iii. One (1) RS-232 & One(1) RS-485 serial communication port.

iv. The PLC shall be capable of operating in a stand-alone manner, with full functionality, independent of communication with the Master station.

v. In case of a communication failure with the master, the PLC shall be capable of archiving data points. The number of points shall be specified in the PLC Specific Requirement Sheet.

vi. Upon recovery from communication or power failure, the PLC shall be ready to accept automatic download of database changes from the master station and also it shall be ready to respond to a poll request within 30 seconds of re-establishing communication.
6. Environmental Conditions:

Operating Temperature range: 10° to 70°C ,
Relative Humidity:15-95% non-condensing

Please suggest me a PLC .
this looks like it came directly from the GEIP playbook.
www.ge-ip.com
 
Tom Jenkins beat me to it. I agree with Tom's assessment that they have something in mind already. It pays to ask.
 

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