MLX 1400 with POINT I/O

JeffKiper

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I was talking to a customer on the phone. Sick kids so I couldn't get on site for a face to face.

He wants me to quote against a guy that is using 1734 point I/O as distributed I/O for a system. No problem except the controller is a MicroLogix 1400. I respectfully declined to quote the system that way.

He wanted to know why. I explained the just because you could doesn't mean you should.

I am thinking of the new 1769-L16 processors has anyone used them with Ethernet I/O yet? Good bad otherwise?
 
I can't completely discount the remote theoretical possibility that you could use CIP generic messaging to read at least discrete Input module data from POINT I/O with a MicroLogix 1400.

But that is not a feature that is intended, designed, advertised, or supported for the MicroLogix 1400.

The CompactLogix 1769-L16ER and 1769-L18ER have a low-powered local POINT I/O scanner, but remarkably powerful Ethernet capacity. You can run up to 4 EtherNet/IP adapters with an -L16ER and up to 8 with a -L18ER or -L18ERM.

The MicroLogix 1400 fits quite a lot of applications, including stuff with high-speed local I/O and multiple RS-232 and RS-485 ports. But for small applications with distributed POINT I/O on EtherNet/IP networks, the new CompactLogix controllers are the way to go.
 
I spent a whole 5 or 10 minutes looking at the Point I/O manuals and found where you can do CIP reads to get the Input data. I ASSuME you could set the Output data again I am NOT going to quote this job that way.

Ken Have you gotten a chance to play with these L1 processors yet?
 
I have two machines being assembled now with 1769-L18ER controllers.

So far, I'm very pleased with them.

I got the -L18ER model just to be conservative; I didn't know for sure what my application program size would be. Turns out I could have used the -L16 easily.

The USB connection was falling-off-a-log simple. The Ethernet daughtercard has some subtle things that are new about it (no CIP hop to the backplane required) but has plenty of connection horsepower; no more running out of CIP connections because somebody left RSLinx Autobrowse running.

I like the SD card storage. I have three programmable devices in the control panel and all three use SD cards formatted as FAT16. The backup files all go into different directories, so there's no conflict when putting my HMI, PLC, and audio annunciator files onto the same backup card.

I'm a little disappointed with the horsepower of the local POINT interface; it takes about 20 ms for each Analog/Specialty module. POINT attached via EtherNet/IP can run faster, and the local discrete POINT is plenty quick.

Don't try to do field terminations directly to the onboard I/O; they're OK when you're making a harness to go to a set of field terminal blocks, but too small and crowded to do field terminations directly. I do perform field terminations directly to local POINT modules.

Yes, the CompactLogix is still more expensive than the MicroLogix, but the difference is small enough that if I can save even a day on program development, I'll do it.
 
Ken does that SD get used just for the PLC or does it have some type of auto recovery for the new PV+6? Probably not yet but I see it coming to this as one integrated package. Thanks for the heads up
 
I'm not totally clear on how the nonvolatile RAM in the CompactLogix 1769-L1x controllers works. The controller happily keeps the program over the weekend with the power off and the SD card removed, but I know it doesn't have a battery.

My guess is that it's like the 1756-L71, where there's an onboard NVRAM that it writes to during powerdown. The supercapacitor can keep the clock running for a few days or weeks, but the program is stored in onboard NVRAM.

The SD card is just a removable nonvolatile storage device; you can burn the CompactLogix memory image to it, but you don't have to.

My plan is to store the PanelView Plus and the Patlite annuciator backups on the same card (since both of them have nonvolatile memory that is more or less permanent), and leave the SD card in the CompactLogix.
 
I did a 1756-L60M03SE a few years ago and placed all the .DWG .PVA and the PowerFlex file onboard. Then I always had it there when I got onsite that the plant lost the print that where shipped with the unit. etc.etc.etc... we have all been there a couple of times at least.
I am waiting for the ftp use of the onboard CF or SD then we don't even have to stop the process to get the development files for the system
 
banani

I spent a whole 5 or 10 minutes looking at the Point I/O manuals and found where you can do CIP reads to get the Input data. I ASSuME you could set the Output data again I am NOT going to quote this job that way.

Ken Have you gotten a chance to play with these L1 processors yet?

Which manual did you find the message instructions
 
Message (MSG) instructions are described both in the Online Help and in the Reference Manuals for each controller family.

For the MicroLogix 1400 controller, the MSG instruction is described in Publication 1766-RM001, starting in Chapter 22.

DO NOT attempt to use the MicroLogix 1400 as an I/O master to POINT I/O devices. That was the whole point of this discussion in 2012, to confirm that Jeff's competitor had quoted a system that could not function, and the Jeff was correct to not attempt to compete with the same network architecture that was incorrectly conceived and doomed to failure.
 
All Rockwell Automation I/O products are meant to be used with controllers that implement formal I/O protocols.

There are no supported ways to make a MicroLogix controller emulate I/O scanning by using MSG instructions.
 
I second Ken's statement about Micrologix not supporting remote I/O. Don't use the Micrologix for remote I/O.

Ken what are you doing up at 3 am your time?
 
I'm in Nagoya again, for 787 production stuff, so it's just 9 PM on Friday night here.

The appropriate question is: "why are you on PLCTalk on a Friday night ?"

:)
 
Go out and see the town. Enjoy a nice meal for me. I have living off fast food joints.
My wifes question is why am I awake at 7 am when I didn't get home until 2 am.
 

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