Ethernet - screw

Hello together

My problem right now is that i got a Compactlogix 1769-L32E
Controller with a whole bunch of 1734-AENT PointIO Adaptors
and my ethernet connection is not working properly.

For example: When I´m connecting 2 of my AENT´s to the
ethernet everything is working normally.
When I´ve 3 or more I´m getting everytime a Minor Fault
at the controller himself (Watchdog).
Also I can´t go online or download anymore over the network-
connector (through ethernet switch) in RSL5k.
(RSLinx is still working over ethernet in this case.)
As I say: this is only happening when I got 3 or more
AENT´s connected.

I´ve already been told to split my program to fix this fault.
Right now I made it like this that I´m saving all of my input
signals on to internal bool-variables in an extra periodic task
(period is 200ms).

The logic is in the main task with the stock watchdog of 500ms.
But there is right now not that much active that it can hit that
time I think.

When I´m looking at the scan times I´ve got 400us at the IO-task
and 5ms max at the main-task.

Anybody got an idea what can be wrong?

You probably have "too many connections" at "too fast an RPI rate".

You need to post the exact I/O configuration of your controller for anyone to assess if the Ethernet port is overloaded. You should also post the exact RSLogix 5000 fault text that accompanies the watchdog fault. Watchdog faults are Major Faults and should halt the controller.

It would be easiest if you simply posted your RSLogix 5000 file to the Forum and someone else with RSLogix 5000 can help you count the connections and RPI rates and compare them to the capacity of the 1769-L32E controller's Ethernet daughtercard.

RSNetworx for EtherNet/IP also performs these kinds of calculations, and will tell you how much of the Ethernet interface's CPU utilization a given set of connections will take up.

Please post the RS5000 file here.
I'm sure we can help you fix this.

Here you got it.

Right now I decreased my program to a test program where only
some connections are made.

In the first periodic task there is the IO (saving the IOs onto
internal variables) and in the second periodic task is some logic.

It was getting a little much better when i disabled the keying
at the AENTs. But I have still troubles sometimes with the com.

The fault I got at the controller everytime was only a minor fault
(watchdog checkbox enabled) but there was no information else.

I think it came from the AENTs himself or their daughter modules.

What is an usual rate you can choose for your RPI when you
have lets say 6 or 7 AENTs?

Change "connection" for all digital I/O modules from DATA to Rack Optimization, you are running out of connections

Set AENT RPI as needed for fastest digital module (10-20ms is typical)
Remove all PV entries from the tree, they should not be there

Also local modules at 2 ms are little too fast - are your sure you need 2 ms?

Rack Optimization

That's definitely it; RSNetworx for EtherNet/IP reports that you're using 137.50 % of the controller's connection resources, just for the POINT I/O modules. You have 41 I/O connections configured, while CompactLogix supports 32 scheduled connections.

The solution is to rack-optimize the discrete module connections. That drops the number of connections used by POINT modules and adapters to 12. v15 of RSLogix 5000 lets you change the I/O connection type without deleting and re-creating the modules.

You can use those I/O connections for EtherNet/IP PanelView terminals if they are Standard PanelViews. The PanelView Plus does not use I/O connections, and creating them in the RSLogix 5000 I/O tree can interfere with the PanelView Plus's network operation.

Ken,
Correct me if I'm wrong but pannels and HMI take up to 5 connections from the 32 connection limit. This depends on the number of tags on the current screen.
RSLogix also takes one connection

Hmm, okay I threw out now the panelviews.

But when I open the properties of an AENT there is allready

standing Rack-optimazation in the box. Also it is greyed out

so I cannot change it, only when i make a new one.

And its still the same: I have no longer a minor fault at

the controller, but when I am connecting more than 3 AENTS

on the network switch, I cant go online anymore with the

ethernet driver.

Also I have everywhere 80ms at the AENTs and 40ms at their

daughtercards (IOs), so that shouldnt make any troubles

I think?

You need to change the digital cards to Rack-optimazation.
the reson why after you connect 3 AENT cards you cant log into the controller is because you are over the 32 CIP connection limit.

you can open an internet browser and write your 1769 controller address,
you will be ablt to fined two important numbers:
1. number of CIP connections (32 is the limit)
2. number of IO packets per second (4000 limit I think)

good luck

You need to change the connection type of the digital POINT I/O modules themselves to Rack Optimized.

In the Properties window for each 1734 discrete module there will be a section labeled "Module Definition", with a "Change" button.

The window that comes up when you click "Change" allows you to change the I/O connection from an individual Module connection to a Rack Optimized connection (which is the default).

I think this feature was added in Version 15, so if you are running Version 13, you will have to delete and re-add the POINT module with the same name.

This program already in ver 15, so it will be easy to change
Must change all digital modules

Err..

When I am opening that properties I cannot choose Rack Optimization

because its missing.

But I have V15 of RSL5k.

Rack Optimization will be missing in the analog cards, It is available in all digital cards.

This screen shot 2 posts above is from your file - how can you miss it? As you see Rack Optimization is there.

Yeah I see but

unfortunately I have got only Exact Match, Compatible Module and

Disable Keying to choose. But as I say I have V15.
Maybe somethings wrong with it?

But it is working when I am making new ones.
Damn, so I need to make my whole IO Configuration again.

By the way, if not made in the IO Config, how is a
Panelview Plus connected to the PLC?