AB PLC Selection - HELP

[mrmss]

Hi,

I have five years experience with Siemens, but I have my first automation project as a contractor and its AB! I am trying to spec the hardware, I think the MicroLogix 1500 fits the bill as the application functionality is very straight-forward, but I'm not comfortable with 12k for a sequencer plus all the alarms and recovery which comes with it.

I/O count is:

• 45 DI
• 12 DO
• 18 AI

Two questions;
1) What does 12k buy you in logic terms? Can people give me some practical examples of what functionality you have build in the MLX 1500 with a 12k CPU.
2) What are my alternatives, project cost sky-rockets when going to CompactLogic (CMX?) as I am then in Logix5000 teritory and I strangely have alot of AI.

Look forward to hearing about your projects, Thanks in advance.

 

[Kidblue]

Hi,

From a personal point of view I would go for the Micrologix 1400 (if only for the built in ethernet port and 2 x serial ports). It has 20 DI and 12 DO built in and can support up to 7 expansion modules...

DI - 20 (built in) + 1 off 1762-IQ32T
DO - 12 (built in) as required
AI - 5 off 1762-IF4

This is just the way i would tackle this one (there are many alternatives!) - the software is the same (essentially) across most of the Micrologix range so the ML1400 will still use what you were planning to use with the ML1500...

It's the flexibility the ML1400 gives with programming via ethernet we tend to prefer, but as stated, others will have their own route they would take!

Hope this helps!

(where in the Midlands are you based?)

Regards,

Rob

 

[mrmss]

Hi Rob,

Thanks for the reply - I'm in Leicestershire.

The option you suggested would use all the slots and leave no room for expansion and my customer is very indecisive so I would prefer to have a future proof solution.

How much memory does the 1400 have? Can you give an idea of the sort of projects you run on them and the features implemented.

What I mean by that is...Number of I/O, Auto Sequencer, Manual Control, Semi-Auto, Recovery Sequences, Alarms, HMI interface logic, third-party handshakes.

 

[bkottaras]

I would be very scared using up all the available slots up front.
I've been bitten a few times in the past by doing so.
Drop the Micro, go with a compact series (L32E) so you have ethernet and a serial port and use high density modules so you only set up one rack with 8 slots available.
Future expansion is possible at any time, only thing you need to replace will be the ECR end plate on your current system.

 

[mrmss]

hi bkottaras,

The MicroLogix 1500 can have 16-solts so it gives me just as much room for manouver as a CompactLogix would, FYI the 1500 uses CompactLogic I/O modules.

Only part I'm unsure about is the 10k user data, hence the question - what have people done in Logix500 with 10k of user data?

 

[Paul B]

The #1 drawback to the ML1500 is no online edits.

I have a client with 12 presses, each with a ML1500. It's a manufacturing operation and I was hired to add new products to the presses. The programs were quite large but I was still amazed to find it took 2-4 minutes to download a program change. Each time a change to the machine was needed I had to stop the CPU and wait.... serial only downloads at 19,200 took painful minutes.

The ML1100 or the ML1400 has online edits, plus an Ethernet port.
However with your I-O count I would steer you to the CompactLogix L32E, as previously stated.

I would be happy to send you one of those press programs so you can "see" how much logic a full ML1500 program has. PM me your email address.

 

[(8{)} ( .)]

I'd recommend going the Compact Logic route. In addition to being expandable you've also got the ability to define user function blocks and data type. From someone moving from Siemens to A-B this functionality is a huge plus. While the SLC family (MicroLogix) will do the job the programming platform is an aging one. The CLX platform is far more modern and versatile. It may cost you a few extra sheqels up front but you'll save a ton of engineering time.

Good Luck,

(8{)} .)
(Yosi)

 

[mrmss]

Okay, I'm going with CompactLogix - I suppose I also wanted to be sure I would be able to justify the additional expenditure, if challenged.

@PaulB - I will take you up on that offer as a learning experience, I'll PM you.