Allen Bradley 1756-ENBT Module Timestamping

[jjimen03]

Hello all,

I have a ControlLogix controller with an Ethernet/IP module installed and communicating with an iFix HMI. The Ethernet/IP module ( 1756-ENBT ) sends data to the HMI, such as alarms for example. We see the tag data in the HMI alarm logs with their corresponding timestamps ( Time at which the Binary Tag changed state for example).

My question is, where does the timestamp come from? Is the ControlLogix PLC time-stamping the data, is it the Ethernet/IP module, or is it the iFix HMI SCADA software?

The HMI alarm logs also display alarm data received from DNP slaves, but when I compare the timestamps between data received from DNP slaves and Ethernet/IP sources, the time seems off by a few seconds or so sometimes.

Thanks in advance.

 

[dmargineau]

It probably is the HMI timestamp; unless programmatically implemented (CPU application and HMI setup) the default timestamping is local system variable defined in most of the modern graphic terminal platforms.

 

[labeledas]

I would say it's hmi time as well

 

[harryting]

Someone more knowledgable can chime in but my understanding is that if you want msec level timestamp with Logix you will need FactoryTalk Alarm and Event. Which is include in FactoryTalk View SE.

 

[Ken Roach]

It's almost certainly the HMI timestamp when it reads the data change from the controller.

Rockwell designed the "FactoryTalk Alarms and Events" system to allow (among other things) precision timestamping of events that happen in the controller. But that requires the whole FactoryTalk subsystem and ALMA and ALMD instructions in the controller, which wouldn't be available to iFix.

One of the standout features of DNP3 protocol is the built-in timestamping with the data packets, so those are the ones whose driver I would expect to adopt the time stamp and use it in alarming.

 

[harryting]

Ok, that's sound about what I remembered. To me, that's a huge selling point if Rockwell de-couple that functionality to allow standard OPC to access the timestamp in Logix.

I also been waiting for a good Ethernet/IP - DNP gateway but most of what I have used are difficult to manage and buggy. It's weird that no one step in this void. I will ask the ProSoft and SEL rep if they are planning on putting out something better if I make it to the RAOTM in Portland at the end of the month.