Failsafe DI-signals in S7-1200 Failsafe CPU

Hello,

I am currently working with Failsafe CPU & Failsafe signals and was wondering, how am i supposed to address my FDI- signals. 

In the attached picture, i assigned the starting address of I40.0 to the FDI-card, which leads to my "I/O-tags" list being from I40.0 ... I43.7.

The card i am using is only a 16 channel card, so which addresses am i supposed to use? Are these I40.0...I41.7 correct, which i have now chosen and why is the list all the way to I43.7, even though it is not a 32-channel card?

I am using 1oo2 for my signals, which is why i have named them as A & B.

Cheers!

Hello,

The first 2 bytes are Process value bits

And the last 2 bytes are Value status bits.

When you use 1 out of 2, be sure to use the right channels.  DIa.0 and DIb.0

(in your example I40.0 and I41.0 are used together)

Best regards,

Wizard

Oh yeah you are right. So my 1oo2 signals should be:

Signal A = I40.0

Signal B = I41.0

I quess that in the actual program, to cause a shutdown lets say i am supposed to use the Process value bits. But in what case are the Value status bits used?

BR,

Aleksi

Hello,

You can use the Value Status bits, to be sure a valid Process value.

Or it is a Fail-safe value, in case of an error.

Best regards,

Wizard

Thanks alot!

[snip]

BR,

Aleksi