Newb - working with MicroLogix 1500 and Modicon Quantum PLC

work_term_guy

Member
Join Date
May 2007
Location
At my house
Posts
1
Hi,

I'm on a work term in a pulp and paper mill for my engineering program at the moment and I've been throw in the deep end with PLCs. I haven't learned anything about them in school but I'm working pretty much exclusively with them now. It's intense but it's a good way to learn.

My main task is to upgrade a chemical system. We are replacing an existing SLC 150 with a Modicon Quantum 14 CPU 113 03 to control a mixing unit. I had to write a program in ModSoft for the new PLC based on the old program - The first time I saw ladder logic was three weeks ago but I have finished it and it has been verified by someone else. It'll be going on the new PLC next week and hopefully it'll work alright.

My problem now is that I also need to consider an additonal, new mixing unit. It has a MicroLogix 1500 controller. From this PLC, I need to send data to the Quantum so the Quantum can send this data to the DCS. My supervisor has suggested I use a 140 NOM 212 00 Modbus Plus Network Module on the Quantum rack and a MVI46-MBP Modbus Plus Communication Module for the ML 1500.

I guess my questions are:

1. The Micrologix 1500 is preprogrammed and I don't have access to the ladder logic. Is there anyway to download it from the PLC?

2. How many expansion modules (I/O or communications) can the 1500 power without using a 1769-CRRx expansion cable? I have a pile of literature in front of me and all the examples show two exansion modules on the base unit. There is no space in the panel box for an expansion. I was hoping to stick the Modbus module onto the other two already there.

3. Will Modbus Plus work with these PLCs? The AB literature says to use the 1500 as an Modbus RTU Master is need FRN 9 and higher and to use it as a Modbus RTU Slave, I need a 1500 1764-LSP Series B or higher. I have a 1500 1764-LSP Series A Ver A FRN 1.

4. Are there any other/better ways to connect the two PLCs? I need to send a small amount of data, something like the status of maybe a 16 bits every scan.

5. How do I set up Modbus Plus in Modsoft?

I know that I'm kind of asking for a lot of help here but any help would be greatly appreciated.

Thanks,
Jon
 
1. You can upload the program from a ML1500, if its not secured with a password. You need Rslinx and Rslogix500.
2. The number of module the micrologix 1500 accept withpout expansion depends, each module consume diferent amount of current in 5vcc and 24 vcc, you have to calculate it and see if its ok. In any case a Ml1500 base accepts max. 8 modules without expansion ( if there is no proble with current!!).
3. You need the plc with the firmware ab says. otherwise i don´t think it will work.
 
As you read the manuals, do not confuse Modbus (master - slave) with Modbus Plus (peer to peer).

In 984 Ladder Logic (Modsoft), the MSTR command is used for Modbus Plus communications.
 

Similar Topics

We have a product we are now building and are planning on using RFID tags to ID trays of product as they move through the process (5 individual...
Replies
6
Views
1,363
hello, Ive never used factory talk before, working on a project that has a close deadline im getting errors expression contains tag that has an...
Replies
15
Views
5,215
High everyone. I am just getting familiarized with PLC's for my new job. Anyways I have set up a test PLC with a button, a photo eye and an...
Replies
7
Views
2,671
First time ever doing profinet or profibus or anything on a siemens. I've only ever used discrete IO with it. So when I add a servo drive to the...
Replies
6
Views
3,257
Hi everyone, could really use some help if you get the chance!! Trying to create discrete I/O tag with an micrologix program. Green light on...
Replies
2
Views
1,516
Back
Top Bottom