Real time project with Micrologix

[rsdoran]

I have recently taken a new job and my first project is a fairly simple one. I am going to turn on a pump and chiller an hour before production starts. In the future other items may be added to the process...air compressor, extruder heat etc. I am involved at the start of a new process with all new equipment in its own building with management that wants processes automated.

At this time I dont need but 16 I/O with a RTC (real time clock). The company has decided to standardize on AB either MicroLogix or the SLC at this time.

What I plan to do is program the plc to look at day of week..ie 0=Sunday 1=Monday etc and turn on the chiller/pump for that day if scheduled. I will need to use an Operator Interface to modify for holidays and unscheduled work days. I may also schedule off time and in future more items will be added to the process.

I looked at the MicroLogix 1000 but couldnt see where RTC was available so I am looking at the ML1200 with RTC and a MicroView as the operator interface. I may up to an ML1500 to get 2 ports and more expansion options but not sure yet if the cost will be a factor.

My Question
Will the ML1200 with RTC module with the MicroView (2707-MVP232) offer the ability to create screens to modify the day to day needs? I have read thru the manual for the MicroView and it looks to me like it will work but I wanted to verify it. I believe the ML1200 with an RTC should allow me to use a compare instruction to verify time on a day to day basis.

 

[PhilipW]

The Micro 1000 did NOT have an RTC, but the 1200 and 1500 do have one as a plug-in module.

When present the RTC appears on a tab in the status file, and gives access to RTC datatable values that get used in the program like any other.:

 

[LadderLogic]

If I am not mistaken, you can use MOV instructions with RTC function file (real-time clock).

MOV RTC:0.YR N7:0

Note the format of the RTC word (in this case, the year). RSLogix help file is somewhat misleading on this.

Unfortunately, unlike SLC500, you can only read the real-time clock, you cannot write to it.

 

[Tom Jenkins]

I have used the 1200 with the RTC module for a scheduled operation. The individuals are correct - you can read the RTC and use the MOV instruction to access the time, date, etc. but I couldn't write to it to reset the clock except from RSLOgix. That isn't a big problem if you have RSLoigix available, but it can be for an OEM system.

 

[rsdoran]

As long as the clock maintains the proper time I wont need to write to it.

I was more concerned with the abilities of the OP.

Thanks

 

[Thomas Sullens]

MicroView (2707-MVP232) I don`t see this cat. # in the PanelVeiw Standard Operator Terminals user manual is this a new one?

 

[Jnelson]

Does the RTC update automatically for daylight savings time?

 

[Eric Nelson]

The newer firmware allows changing the RTC values (except day-of-week) from logic...

See THIS application note...

beerchug

-Eric

 

[rsdoran]

I have decided to use the ML1200 (1762-L24AWAR) that has 2 comm ports and 1762-MM1RTC memory module with real time clock. I will be connecting to a PV300 micro for the operator interface.

The PV300 should have the features I need and the ML1200 offers expansion options for the future.

Thanks for the assist.

 

[JesperMP]

As long as the clock maintains the proper time I wont need to write to it.

Any clock will show an error given enough time. And dont expect the RTC to be as precise as an expensive timepiece. Just look how the clock on a regular PC drift substantially over the time.

 

[Bob O]

Jnelson

The RTC dose not account for daylight savings time. I have my Micrologixs 1500 on the network and use RSView systemtime to set the time using CPW once a day and when the machine is powered up.

Bob O.

 

[Matthias von Zorn]

My required ML rant...

Dont forget, no online edits for the ML line!

Matt

 

[LJBMatt]

I thought the ML 1500 allowed for online edits? Only the ML 1000 and 1200 you had this restriction.

 

[Matthias von Zorn]

Maybe it has changed????

Last time I used (about 1-1/2 years ago) them, there were no online edits. The 1500 is the only ML ive used too.

Matt

 

[JesperMP]

The ML1500 product homepage doesnt mention anything about online editing. It would be a major selling point if it had, so I think they would display it prominently as a "feature".
In the new Logix family hierachy, online editing starts with CompactLogix.