PLC's, best price and performance

Let's get some opinions, which PLC all around offers the best PLC's, best price, performance and reliability in the following ranges?

1 Mini-Micro 2 Expandable Shoe box 3 Midrange 4 Hi End
Reply to
Dennis Mchenney
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My 2c worth:

Mitsubishi FX - or maybe Omron. Naah, definitely Mitsubishi.

Mitsubishi again - assuming you don't want comms. If you do, then either AB CompactLogix or Schneider Momentum depending upon exactly what comms.

Siemens S7-300 by a long way.

Probably AB ControlLogix by a small margin from Siemens, Schneider/Modicon et al - depending upon what you need to do (motion control? process control??) and what you want to talk to (Profibus? DNet??)

You might like to expand on your requirements a bit. eg. if you need CPU or PS redundancy, then the race is completely different.

Cameron:-)

Reply to
Cameron Dorrough

Dennis Mchenney wrote in news:Kbmvf.2809 $ snipped-for-privacy@newsread1.news.atl.earthlink.net:

My thoughts....

Never had an application for one, so no opinion

I like the Siemens S7-200

Siemens S7-300 hands down

Depends..for motion control, i.e. NC, Siemens is the cats ass... For process control, i.e. automation, AB ControlLogix is the cats ass...

Reply to
Anthony

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That should read AB *MicroLogix* - CompactLogix isn't a shoe box type - sorry.

Cameron:-)

Reply to
Cameron Dorrough

A-B MicroLogix is a good choice if you only need serial communications in an RTU or stand-alone system. For one client, I just received the parts to replace an ML1500 with an SLC-5/04 so that we can get this last panel onto the DH+ network and the program into Cimplicity Manager.

Momentum offers Ethernet processors and Modbus Plus options modules. On my last big project for my previous employer, each of the 10 filters had a Momentum with MB+ for the network, Modbus RTU from the RS-232 port to the Exor HMI, and Modbus RTU from the RS-485 port to the 7 valves. Next time, I'd recommend an all-Ethernet solution for the HMI and network to the consulting Engineer.

Mike

Reply to
Mike Lamond

Mike, I must admit that I haven't had a great deal of exposure to the Momentum system and most of that was heresay, but we have tendered for a large project with an existing Momentum network on MB+ and are thinking of using some of the Momentum gear as remote I/O drops (including some remote Modbus RTU comms) back to a TSX Quantum PLC system and Ethernet SCADA.

In your experience, what was it like to set up? Pretty straightforward or a right pain in the ass??

Thanks, Cameron:-)

Reply to
Cameron Dorrough

Cameron,

I did one job with Compact 984's and MB+ distributed I/O to Momentum bases in the remote panels. Each base had an MB+ communications adapter using one node on the network. In Modsoft, I configured the Peer Cop for each node, using 00001, 10001, 40001 or 30001 as the starting memory address, depending on the base type. It worked on the second try and has been running for about five years now. With a Quantum, you'd have to do the same thing since the Modbus Plus NOMs only support Quantum distributed I/O. You can also leave the existing Momentum CPU's in place for I/O management, move the existing logic to your new PLC and use the Peer Cop or the MSTR function to move I/O data over the network. It depends on how you trade off new hardware vs supporting multiple PLC programs.

Regards, Mike

Reply to
Mike Lamond

Mike, thanks for the heads-up.

One last question: Would going to Ethernet make things any easier? If so, how so??

Thanks, Cameron:-)

Reply to
Cameron Dorrough

Cameron,

The answer to that is a big "it depends." Converting the processor base to an I/O drop is just a matter of replacing the processor and option adapters with the comm adapter set to the desired node address and plugging the MB+ cable back in. If you have expansion I/O (Interbus S as I recall), that means adding a MB+ connection for each base. I prefer the T-connector kit and drop cable to the inline connector, unless you're truly close on total cable length. If most of your panels have multiple bases, you might as well convert to Ethernet with a dual Cat 5 home run (1 spare) and an industrial hub in each panel. In a new installation, I'd recommend Ethernet. There's more initial configuration involved, but you have all home runs instead of a network layout. Plus, I think there are now more installers who know how to terminate and test Cat 5 than MB+. I really don't want to repeat the job where half the inline connectors were ruined or the other where they broke the tee connectors by punching down 16 AWG instead of the specified 22 AWG cable.

Regards, Mike

Reply to
Mike Lamond

Thanks, Mike - I'll let you know how things turn out.

Reply to
Cameron Dorrough

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