Communicating with MicroLogix 1100

[ftacliad]

Hello All,

I'm hoping someone would be able to shed some light on my situation:

I have a MicroLogix 1100 and I am trying to send it CIP Common Service requests. I have built a library using Python to communicate with devices over EtherNet/IP. The device will respond to the following:

EtherNet/IP:
List Identity
List Services
Register Session

CIP:
Connection Manager Forward Open
Connection Manager Forward Close
PCCC Execute Service - Protected typed logical read with three address fields CMD=0xF FNC=0xA2 (note this CIP service is 0x4B and vendor specific to AB devices)

I want to be able to send the ML 1100 Get Attribute List, NOP, and Multiple Service Packets, but the ML 1100 does not respond. I've started off with Get Attribute Single requests to the Identity Object, but I get nothing. Do I have to encapsulate CIP Common Service requests in PCCC? Any help would greatly be appreciated.

V/r
Frank

 

[Archie]

You are probably looking for the service code 0x4B (execute PCCC)

See page 12 of this document:

https://www.rockwellautomation.com/...ners/technology-licensing/CIPandPCCC_v1_1.pdf

To my knowledge the MicroLogix controllers do not support Multiple Service Requests

 

[ftacliad]

Thanks for your response, Archie.

I have been referencing that document for formatting the structure of my requests, but still no luck. I'll try again tonight and post some pcaps of the traffic I'm seeing.

 

[Archie]

Do you by any chance have a ControlLogix or CompactLogix? Those controllers will support the widest range of commands. Testing with those will verify your code and not have the factor of the controller possibly not supporting the commands.

 

[ftacliad]

Yes! This is part of a research project and the ML 1100 was given to me assembled as a PLC trainer kit. We have a ControlLogix 1756 ENBT-A that I could use, but it needs to be setup. Unfortunately, my deadline for this project is quickly approaching and my advisors are worried that adding another device to test may be too much given my timeline.

I'm going to give myself a couple of more days with testing the ML 1100. If I don't get any interesting results, perhaps I'll just have to buckle down and do as you suggest and test the ControlLogix.