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IE-4000 relay contact configuration/issue?

j.leinonen
Level 1
Level 1

Hi,

I have an issue with IE-4000 relay alarm (maybe same thing with with IE-3200).

We are using NC = Normally closed in all other manufacturer ethernet swithces and we need to do the same with Cisco IE-4000/5000/3200 swithces.

We have connected cable from I/O card to NC and COM in IE-4000 connector.

In normal situation where all is good the relay is closed and no relay alarms.

When port, where we have relay alarm configured, is disconnected relay opens and we get alarm at system side.

Problem is that when IE-4000 goes completely down we are not getting alarm because the Cisco relay stays closed.

In other manufacturer switches relay opens when device goes down.

Is this normal behavior for Cisco IE-models? Or can this be some how changed that if we use NC, it will open when device goes down? note! port alarms still needs to be so that id port goes down relay opens.

 

 

1 Accepted Solution

Accepted Solutions

This reference diagram should help people understand.

BrianSekleckiGE_0-1732574255658.png

 

View solution in original post

6 Replies 6

Albert Mitchell
Cisco Employee
Cisco Employee

you can try to reverse the polarity of relay.

configuration command "alarm relay-mode negative"

this will invert the polarity to negative.

give this a try.   reply back if this works for you.

j.leinonen
Level 1
Level 1

Finally after firmware upgrade too (or I missed something at first test) I got this working.

So I used NO pin and "alarm relay-mode negative"command.

Now if I have port/one power down relay opens and we get alarm.

And if switch goes down relay opens too as it defaults NO as normally Open.

Same tested for IE-3200

This reference diagram should help people understand.

BrianSekleckiGE_0-1732574255658.png

 

BrianSekleckiGE
Level 1
Level 1

BTW, this diagram is valuid for the IE-2000/Stratix 5700 and IE-4000/Stratix 5400, but not valid for the Cisco Catalyst IE-3x00/Stratix 5200/5800.  The relay behavior has changed entirely.  I will post an updated diagram.

 

Stratix 5200 (Catalyst IE-3x00):

Normal Logic:
- Powered off: COM -> NC
- Booting: COM -> NC
- NO/Absent Alarm : Major Soft Alarm: COM -> NC
- Alarm Present: Major Soft Alarm: COM -> NO


Reverse-Logic:
- Powered off: COM -> NC
- Booting: COM -> NC
- NO/Absent Alarm : Major Soft Alarm: COM -> NO
- Alarm Present: Major Soft Alarm: COM -> NC

BrianSekleckiGE
Level 1
Level 1

I confirmed that the new behavior affects the AB-Rockwell Stratix 5200 and Stratix 5800 which are both derivitives of the Cisco Catalyst IE-3x00 (Different sub-families)

I've added some notes here for the Cisco / AB-Rockwell Product Engineers ; about how the default resting position of COM->NC is not a good design (Safety loop circuits in OT/IOT environments assume: 1) To rest in COM->N/O when de-energized and booting 2) To rest in COM->N/C when healthy condition (absence of alarm)  )

That means that, for Cisco IE-3x00, IOT/OT engineers will MOST LIKELY want to:

1) Cable their safety loop from COM -> N/O 

2) Configure switch for INVERSE/INTERVED/REVERSE LOGIC "alarm relay-mode negative"

 

BrianSekleckiGE_0-1736782037193.png

 

 

Albert Mitchell
Cisco Employee
Cisco Employee

Thank You for the posting. 
for future readers, I would like to add there are MANY different use cases for the Alarm relay.  Some installations only want the relay to indicate an alarm when the system detects a specific list of alarm conditions.  They do not consider “powered off” or “booting” to be an alarm-worthy situation.  Some installations want open-circuit to indicate an alarm. Others want a closed circuit upon alarm because they use it to illuminate a tally light.

There’s no single configuration that works for everyone.  Fortunately, the IE alarm relay is highly configurable and can be set up to work for most common alarm circuit topology.