DeviceNet -RSNetworx address problem

Greetings,

We are having a DeviceNet problem here at the plant. The problem occurred after 5 years of operation and a node on the DeviceNet Network getting drenched with water. The problem with the Node is temporarily bypassed in Local control so we are OK for the moment.

This is our first major DeviceNet problem so we ordered RSNetWorx. I have set up a test PLC in an attempt to understand DeviceNet before tackling the real problem.

Test setup is as follows
Laptop --> 1770-KFD --> Micrologix 1500 PLC with 1769-SDN DeviceNet Scanner Card --> Cutler Hammer DN65 DeviceNet I/O module.

RSNetworx maps the Inputs from the DN65 to start at I:1.66. When I then go into the program with RSLogix 500 and look at the Input Data Table it looks like the attached picture with I/O reserved for DeviceNet up to i:1.65 where the inputs end.



I have done a few days of searching and can't find the answer. Can someone explain how I map the I/O properly?

Thanks for any help,
Doug

When using the 1769-SDN with MicroLogix 1500 controllers, I always print out page 17 of the Installation Instructions as a reference to the layout of the Input and Output tables.

With the MicroLogix 1500, the 1769-SDN's Status table fills the first 66 Words, and the actual mapped I/O comes after it. When the same 1769-SDN is used with a CompactLogix, that data gets placed in the separate Status assembly.

The other complexity is that the MicroLogix I/O memory size for this module is variable, in order to save MicroLogix addressing space. The default size includes only the status and command words, and you have to increase the connection size to include the data you've mapped to the module (up to 180 words each, Input and Output).

After expanding that I/O table to allow for the actual mapped I/O, you're probably going to want to interpret that status area. For that you need the full 1769-SDN User Manual, publication 1769-UM009.

The key figure is on Page 88, the Status Table.

What we can see from your screenshot is that there's an active node at Node 01 (the bit set at Word 14, Bit 01). Once you expand the I/O table we'll probably see the actual data.

Ken,

Thanks for the responses. I am looking through your suggested publications and trying to resize the data table now.

Thanks,
Doug

Ken,
Seems to be fine now. For any other novices like me trying to figure this out;

In RSLogix 500 I went to:
IO Configuration -> Adv Config -> Input Words & Output Words and increased the size there.

Thanks again for the help,
Doug