Facing a problem of all DI and AI Signal flicker for about 500ms with unknown flickering time

Hi All,

Thanks in advance for any solution..!

Im using ET 200M module in my RIO with OBT for conversion of F.O signal to Profibus signal.

Now im facing a problem of all DI and AI Signal flicker for about 500ms with unknown flickering time.

Tried changing power supply module,OBT,ET 200M and All DI cards.But the problem still coming.

Looking forward for any good suggetion....!

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Split from ET200M signals problem.

Hi Dsouza,

assuming you are using please 24Vdc measure the supply voltage, if it drops below 18Vdc i have experienced loss of signal for varying time until the voltage picks up again above the threshold which i understand to be >18.3 Vdc

if you monitor the AI value in a VAT table on on the HW Config, does the value go to 16#0000 or 16#7FFF?

Kind Regards,

Hello Dsouza,

what do you change before you have this problem?

It's possible that there are changes near the ET200M modules/PLC?
e.g. new Motors, Micromaster etc. - maybe a problem with shield

In my opinion could it be a problem with the ground of your 24V (broken wiring)
If the connection between your power supply ground (Minus) and your earth ground is defect then could you have the samen problem (undefined ground potential)

Hope this is a helpful suggestion.

regards
CaOd

Thank u so much zunaid sir for  taking time to reply..!

Yeah initially i had doubt in voltage flicker so i changed all the power supply module(415 v and 230 v ac to 24 v dc) with brand new power supply modules.

Yeah i have also checked in VAT Table and also in online data checking software. It shows that at the time of flicker AI values goes to #7FFF.

Also i have provided seperate Electronic earthing to the panel , changed doubtfull field devices and also profibus cable shield has been directly connected to Electronic earthing via cable.

Thank u so much Caod sir for  taking time to reply..!

I have not changed anything before this problem started.i did have doubt on earthing so i seperatly layed a cable from electronic earth point to panel.

Profibus cable shield has been directly connected to Electronic earthing via cable.

Any other solution..!

What exactly do you mean by "Now im facing a problem of all DI and AI Signal flicker for about 500ms with unknown flickering time." this statement. Is one flicker (on/off state) exactly for 500 ms?

On the other side check if your Interface modules have ACT (active) led going off during the flickering period. If it does then its a good idea to also check the fiber optic cable to OBT is lossless and have the correct length/type as recommended in the documentation.

Dsouza

Hi All,

Thanks in advance for any solution..!

Im using ET 200M module in my RIO with OBT for conversion of F.O signal to Profibus signal.

Now im facing a problem of all DI and AI Signal flicker for about 500ms with unknown flickering time.

Tried changing power supply module,OBT,ET 200M and All DI cards.But the problem still coming.

Looking forward for any good suggetion....!

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Split from ET200M signals problem.

Than you Dawg1,

What i meant exactly with my question is that In my RIO all the signals connected are flickering (All DI and DQ will go 1 to 0) and all Ai count goes to (#7FFF) for about 500 ms.

The frequency of flicker is unknown , like sometimes once is a day or sometimes once in an hours or so.