STEP7 -> VAT hanging problem

Mar 17, 2006 6 Replies

Hi, has anybody faced the observation variables problem under VAT ? I have 2 PLC's connected over Ethernet, first PLC I can observe without hanging, second not ...after every hang I have to enforce observation mode pressing again out and in Monitor variable icon (eyeglases icon)



Cheers


The following you may check.

  1. PLC memory full / nearly full
  2. Your size of VAT is big (more than 10variables)
  3. Hubspeed is slow
  4. Your program and hence sacan cycle is too high
  5. Others are connected (i.e the port serves also other devices)
  6. You have the program debug ON

The solution can be to increase the communication time alloted in the whole scan cycle. Regards Balki You may also post the way you solved the problem

Balki napisa?(a):

I checked everything and still i have the problem, furthermore with simplest program i.e. INC value and observing it makes problem :// additionally the same program on the another PLC works.

further you may check this?

  1. distance between PG and PLCs
  2. Cabling and the Hub port
  3. Whether the PLC port works well for other facilities provided for the port?.
  4. Interchange if it is CP for both PLCs and confirm which is faulty? nothing more from my side Balki

distance of both PLCs while checking and via MPI or DP or Ethernet?

distance of both PLCs while checking and via MPI or DP or Ethernet?

Balki napisa?(a):

Finally It was processor defect of second PLC.

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