Hi all. 

I have s7 300 cpu communicate with s7 1200.

On s7 300 I make communication handler which do put and get function.

I set some bit  on s7 300 and transfer it to s7 1200, it works. On both sides bit stay in db which is not retain.

Now for test, I disconnect ethernet cable between cpu-s, when communicatio error detected, on s7 300 side, bit is reset, but on s7 1200 side, bit stay set.

How to detect communication error on partner cpu s7 1200 ? 

BR,

Miloš

Milosh

Hi all. 

I have s7 300 cpu communicate with s7 1200.

On s7 300 I make communication handler which do put and get function.

I set some bit  on s7 300 and transfer it to s7 1200, it works. On both sides bit stay in db which is not retain.

Now for test, I disconnect ethernet cable between cpu-s, when communicatio error detected, on s7 300 side, bit is reset, but on s7 1200 side, bit stay set.

How to detect communication error on partner cpu s7 1200 ? 

BR,

Miloš

Hi.

You can create a "heart beat" signal.

Have your S7-300 pulse a signal ON-OFF.
Then S7-1200 can detect if that bit stays ON or OFF for too long.

Also have S7-1200 pulse a bit for the S7-300 to monitor changing polarity.

w

William_B

Hi.

You can create a "heart beat" signal.

Have your S7-300 pulse a signal ON-OFF.
Then S7-1200 can detect if that bit stays ON or OFF for too long.

Also have S7-1200 pulse a bit for the S7-300 to monitor changing polarity.

w

 Yes, that's it. May idea was to create counter, and check value. If value not changed for some time it can be detected by s7 1200. But this with one bool signal is better.

I thought if there is some bulit-in diagnostics.

What do you mean with "monitor changing polarity"?

Milosh

 Yes, that's it. May idea was to create counter, and check value. If value not changed for some time it can be detected by s7 1200. But this with one bool signal is better.

I thought if there is some bulit-in diagnostics.

What do you mean with "monitor changing polarity"?

 hi Milosh,

when you sending a heartbeat to the other CPU, you need to monitor if the heartbeat really changes its polarity

If it doesn´t change, there is a communication error.

regards,

Milosh

What do you mean with "monitor changing polarity"?

Let me show you in code..

#tonTimeOut(IN := NOT( #readPulse XOR #oldPulse ),
            PT := #TIME_TIMEOUT,
            Q => #Error);
#oldPulse := #readPulse;

¡Hi! 

Any advance on this topic?  Do I still need to use a Heartbeat bit with a timer?

sunday_robin

¡Hi! 

Any advance on this topic?  Do I still need to use a Heartbeat bit with a timer?

 On the passive partner on a PUT/GET, using a Heartbeat is the best way to decect if the communication master is sending.