Hello,

I am using an F-CPU with I/O channel diagnostic enabled (Passivate channel, wire break). A default fail-safe value (0) is sent as channel output whenever i have a channel fault since i am activating the passivate channel option.

my question is how to change the fail-safe value from 0 to another value (100) in F-I/O module.

thanks in advance.

alizon

In your safety program, check in the F-I/O data block if  PASS_OUT is true. If so, MOVE the appropriate fail-safe value into a tag which you will use for further processing. Otherwise, MOVE the process value into that tag. Use that tag in the rest of the safety program; do not read the input directly anywhere else.

 thank you alizon, 

indeed the PASS_OUT is true, but there is no parameter to set the desired fail-safe process value, 

sorry i am a beginner with TIA portal, in comparison with other systems you can choose whether your fail-safe value value will be high value or lower value.

plz see attached F-I/O_DB

Hi Youcefer,

It's not a parameter to set, you simply have to apply some simple logic statements to decide whether to use the input value or the fail-safe value.

In LAD, use a contact ( --| |-- or --|/|-- ) to check for the PASS_OUT value, then use the MOVE instruction to move either the input value or your custom fail-safe replacement value into the tag you want to use in the program.

For example, in SCL:

IF "My_FIO_DB".PASS_OUT THEN
    #Value_to_use := 100; // Custom fail-safe value
ELSE
    #Value_to_use := "MyInputTag"; // Normal value from the actual input
END_IF;

mopS04

there is no SCL in F-program. 

Oops, you are quite right! I'm so used to writing SCL for examples as it's easier to convey via text than LAD code. I'll change the above.

mopS04

You can also not write an F-output that is passivated.

We're not talking about writing F-output. In fact, analog F-output doesn't even exist for Siemens PLCs as far as I'm aware. The question is about using a replacement fail-safe value for an analog F-input that has been passivated.

milladt

Hi Everyone,

I want to use the FS-RVCDP function to send data, There are inputs in this function called SUBBO_00 ... SUBBO_15. I read the Document  (STEP 7 Safety V19 instructions, page 533), but I don't know what are they, (Fail-safe value for receive data BOOL 00) anybody has experience?

 RCVDP in the receive block, not the send block. SENDD.

SUBBO_00 -> 15 are BOOL fail-safe signals transferred from the other F-PLC you are communicating with. The partner CPU that has SENDDP configured and the fail-safe BOOL signals declared to it, you will receive to SUBBO_00 -> in the same order they are in the SENDDP.

Using the insoftware help, by pressing F1 when a instruction is selected, you get the documentation directly. At the bottom of the block help, there are many links to get more info in the safety communication between two cpu's.