Weird issue_Micrologix,HMI

Hi guys,
I have a PU dispensing machine installed at my end having MLX 1200 and 22711-TD HMI.The machine was running fine and suddenly the message starts showing up on the HMI screen, which says the "RTC module is missing, machine locked" & the outputs have been switched off.

The program is OEM locked & hence I cant view or upload the program .The OEM has sent me memory module & a memory card, with which I reloaded the PLC & HMI program but unfortunately , the machine is
still displaying the error.

There is no fault (hardware) on the PLC .I am in a fix trying to understand the reason such a problem.The hardware is all fine, there is no RTC module in PLC ,I have replaced the battery of the HMI unit...but issue still stands!!!

What could possibly go wrong??Is it possible that some remnants of the last program is retained by the PLC , even after reloading the program?

i am wondering if the HMI has a flat battery to keep the RTC internally! it may be in the PLC code that if that is not correct the unit alarms.


do you have a local Rockwell (Allen Bradley) sales rep you can ask for info.


http://literature.rockwellautomation.com/idc/groups/literature/documents/td/2711-td007_-en-p.pdf

EICS said:

i am wondering if the HMI has a flat battery to keep the RTC internally! it may be in the PLC code that if that is not correct the unit alarms.


do you have a local Rockwell (Allen Bradley) sales rep you can ask for info.


http://literature.rockwellautomation.com/idc/groups/literature/documents/td/2711-td007_-en-p.pdf

Click to expand...

Exactly!....I was thinking of the same & hence replaced the battery.The voltage read 2.95V (its a 3V battery) but didnt take a chance though and replaced it with a 3 V battery.

rejoe.koshy said:

Exactly!....I was thinking of the same & hence replaced the battery.The voltage read 2.95V (its a 3V battery) but didnt take a chance though and replaced it with a 3 V battery.

Click to expand...

If you measured the battery not connected to the hmi it may show ok once a load is applied you will find it can be much lower.

Let me know how you went.

EICS said:

i am wondering if the HMI has a flat battery to keep the RTC internally! it may be in the PLC code that if that is not correct the unit alarms.


do you have a local Rockwell (Allen Bradley) sales rep you can ask for info.


http://literature.rockwellautomation.com/idc/groups/literature/documents/td/2711-td007_-en-p.pdf

Click to expand...

Ok, now I replaced the existing HMI with a brand new HMI, but guess what ??.....it displays the same error