Time synchronization via 1756-time

[Arizona]

Dear All,
I am new at this forum, seeking help from you guys and gals.

Scenario:

I have a Controllogix 1756-L71 5570 controller installed with 1756-TIME module. The function of time module is to take time from GPS clock module in NTP format and send it to controller in PTP format. All the status LED's on Time module are OK. Also sync LED is Green. Still the time of controller is not synchronized with GPS clock there is a difference of 45 mins.

Fellows please help. I'll be helpful.

 

[Bob O]

Don't know anything about the module or even that one existed but look into the SSV instruction maybe.


HTH

 

[Arizona]

well Bob 0 if you want I can send you datasheet of module
and what's SSV?

 

[Arizona]

Oh sorry I get it now its SSV (set system value). But I don't think there is a need for such instruction.

 

[chopin]

Do you have the Time Synchronisation enabled in the controller properties?

What is your sync interval?

 

[Ken Roach]

Welcome to the PLCTalk forum community !

What are your application needs for the time reference ? Are you using it to synchronize timestamps across multiple facilities, or to interact with the sun, or as a motion control reference ?

The 1756-TIME is a chassis-resident module built by a South African company called HIPROM. It uses a GPS or IRIG-B time source and serves as a precision time reference for the ControlLogix (and a handful of other features and functions).

There are user manuals, an Add-On Profile, and an Application Note:

https://literature.rockwellautomation.com/idc/groups/literature/documents/um/1756-um542_-en-p.pdf

https://literature.rockwellautomation.com/idc/groups/literature/documents/at/1756-at015_-en-p.pdf

It's not automatic for the -TIME module to take over as the system time reference. You need to set up the module and the ControlLogix CPU as shown in Chapter 4 of the User Manual.

Remember that the Wall Clock Time is derived from the high precision system clock (Coordinated System Time), but it's not the same thing.

There's a Knowledgebase document reminder that adjusting the WCT when you are also running motion has some risks; Answer ID 730060 (Access Level: Everyone)

The 1756-TIME is not commonly used, so it's exciting to have someone on the Forum community using it. Tell us about your application, if you have the time and opportunity.

 

[Firejo]

Tell us about your application, if you have the time and opportunity.

Pun intended?

 

[Arizona]

Yes, time sync is enabled and sync interval is 1.

 

[Arizona]

Ken Roach, my application is just to use it for time stamping and time synchronization between the system of alllen bradley and GE.
FYI... I've also reset the TIME module once then time was perfectly synced for few hours. Indication led's on module, all are ok.

 

[Ken Roach]

Is there a chance that there is a computer in your system that is running the old RSLinx-based "Logix 5000 Clock Update Tool" utility ? That tool does the same function as a SSV to modify the WallClockTime of the controller, and is often used on systems that don't have a central clock reference resource.

https://rockwellautomation.custhelp.com/app/answers/answer_view/a_id/44321

There's no reasonable possibility that the clock is drifting 45 minutes in a few hours, so it's likely that some external device is setting it.

 

[Arizona]

But still after a day or so issue resists.

 

[Arizona]

There is no other system is connected to controller except my PG sometimes. Although there is a HMI (Panelview Plus 1500) interfaced with the controller.

 

[Arizona]

Thanks ken roach and all others for your support. The problem is resolved just by giving power cycle to the controller. All the configurations were okay.