1747-aentr fault

I have a recurring problem with my PLC at a facility. First some details:

I upgraded an existing SLC 5/04 PLC with a 1747-AENTR module and a new CompactLogix L33ER with a number of Compact I/O modules added for expansion. The CompactLogix is connected to a N-TRON 7506-GX2 fiber switch via Cat6 UTP, then 200m of multimode fiber to a second 7506-GX2, and then Cat6 to the 1747-AENTR in the old SLC 5/04 rack. Everything works great aside from the fact that the CompactLogix PLC experiences a major fault at irregular intervals at least once daily. The fault is a loss of communication with I/O module.

(Type 03) I/O Fault
(Code 16) I/O module connection failed on requested module
Port: Ethernet
Module: <module name>
Error: Connection Timed Out

The fault has occurred on a variety of cards in the SLC rack. Each card is configured to cause a major fault on loss of communication. Te RPI of all the cards in the SLC rack range from 250 ms for discrete cards to 500 ms for analog cards.

CompactLogix firmware is 24.0, AENTR module firmware is 2.1

Have any of you experienced anything similar? Any insight as to what may be causing this problem?

Thank you

-Robert

Do You get a comms fault on all of the I/O or just output modules?

All modules. DI modules seem to be the most often to cause the problem.

What I thought may be the issue will send you down the wrong path then. Best of luck

Correction: AENTR Module is version 2.002

I have forced all Ethernet ports to 100-BASE/TX Full Duplex. Autonegotiation disabled.

I have also found some conflicting information in the 1747-AENTR installation manual vs the user manual.

In document 1747-UM076C-EN-E there are multiple instances of the following:

"Rockwell Automation recommends that you check or enable the option "Major Fault on Controller If Connection Fails While in Run Mode" on both the 1747-AENTR device and supported 1746 I/O modules."

In document 1747-IN521B-EN-E under the heading of Understand Messaging:

"Class 3 (Explicit Message) requests through the 1747-AENTR adapter to a specific I/O module may not always receive a response from the I/O modules. In the case where the I/O module does not reply to the request, the adapter responds with an error code indicating a time-out."

I tried disabling "Major Fault on Controller If Connection Fails While in Run Mode" on all cards in the SLC rack, but left the fault enabled on the 1747-AENTR module. After some time the PLC faulted once again only this time the major fault appeared as follows:

(Type 03) I/O Fault
(Code 16) I/O module connection failed on requested module
Port: Ethernet
Module: 1747-AENTR
Error: Connection Request Error: Connection Timed Out

It appears I am losing connection between the CompactLogix PLC and the 1747-AENTR module in the SLC rack. I have checked all settings in the N-TRON 7506GX2-SX Ethernet switches and cannot find anything that would cause connection interruptions of any sort.

I also found the following in the document 1747-UM076C-EN-E:

"IMPORTANT: The Chassis size value equals 1 (for the adapter) plus the number of I/O modules installed or physically present on the I/O backplane."

I have 11 I/O modules in the SLC rack, but my chassis size is set to 13 in the AENTR module configuration because I have a gap in the rack.

IE.

SLOT 0 1747-AENTR
SLOT 1 1746-IB32
SLOT 2 1746-IB32
SLOT 3 1746-OW16
SLOT 4 1746-OB32
SLOT 5 1746-OB32
SLOT 6 1746-NI16I
SLOT 7 1746-NI16I
SLOT 8 1746-NI16I
SLOT 9 SPARE
SLOT 10 1746-NO8I
SLOT 11 1746-NO8I
SLOT 12 1746-NR8

I checked and because I have a card in slot 12 I cannot set the chassis size to 12. If I were to move the 1746-NR8 card from slot 12 to slot 9 then I am allowed to decrease the chassis size to 12. Does the AENTR module not allow gaps in the rack? Should I move the 1746-NR8 card to slot 9?

ISSUE RESOLVED

The N-TRON 7506GX2 switches were interrupting network traffic while servicing the Spanning Tree Protocol. Disabling STP in both switches has allowed us to run fault free.

Im in searching this 08 channel analog output card 1746-NO8I but not available in pakistan any alternate? (all 08 channel in use)

Im in searching this 08 channel analog output card 1746-NO8I but not available in pakistan any alternate? (all 08 channel in use)