Siemens S7, SFC83,84 problems

[JockeData]

Hello!

Im having some urgent problems.

Im in need to move my recipes to the MMC card.

The problems im having here is that when i use the SFC83, 84 to Write and Read data on the MMC i get the error/retval: 80C3.

I have tried the exact same code, dbs and everything involved on my test station where it works. But when i try it on the live PLC i cannot get it to work.

I do not use the SFC83,84 anywhere else in the code. Only 1 read and 1 write.

The PLC im using is a 317F-2 PN/DP.

Im happy for all the suggestions.

 

[sigmadelta]

Use the "BUSY" parameter to prevent the SFC83/84 from calling too many times.

You may be using 1 read and 1 write, but they may not finish within a scan, and it can call again while the first one is executing.

 

[JockeData]

Use the "BUSY" parameter to prevent the SFC83/84 from calling too many times.

Yea, im doing this. Still nothing. Im only letting one of the SFC83, 84 functions be active at a time.

 

[sigmadelta]

Did you try execute REQ with a one-shot?

 

[JockeData]

Use the "BUSY" parameter to prevent the SFC83/84 from calling too many times.

You may be using 1 read and 1 write, but they may not finish within a scan, and it can call again while the first one is executing.

Did you try execute REQ with a one-shot?

Did now, and it does not write or read from the card it seems

 

[sigmadelta]

hmm, maybe use a bit that is SET for REQ, and use BUSY to reset the same bit.

Something like this...

SET a bit for REQ SFC 83
when BUSY becomes 0 (falling edge) RESET bit for REQ SFC 83 (this would need a parallel instruction to RESET this bit if the RET_VAL is <> 0)

same for REQ SFC 84..

but, use the BUSY bit from the opposite instruction to block the other... if you know what I mean.

 

[JockeData]

hmm, maybe use a bit that is SET for REQ, and use BUSY to reset the same bit.

Something like this...

SET a bit for REQ SFC 83
when BUSY becomes 0 (falling edge) RESET bit for REQ SFC 83 (this would need a parallel instruction to RESET this bit if the RET_VAL is <> 0)

same for REQ SFC 84..

but, use the BUSY bit from the opposite instruction to block the other... if you know what I mean.

Same here, the BUSY bit never goes high and therefore never low. So the triggerbit for REQ never gets reseted.

 

[sigmadelta]

How much free space is on the MMC? and how much data are you trying to write?

 

[sigmadelta]

What happens when you use bits and set them yourself in a VAT table?

 

[sigmadelta]

Capture the BUSY bit using a SET coil on an unused bit, to really be sure the BUSY is actually turning on. It may be happening too fast to see it.

 

[sigmadelta]

What's the version of firmware/operating system in your test PLC and the 317F-2PN/DP?

 

[JockeData]

How much free space is on the MMC? and how much data are you trying to write?

About 3MB free space, with this test im only trying with a word.

What happens when you use bits and set them yourself in a VAT table?

Same result as above.

Capture the BUSY bit using a SET coil on an unused bit, to really be sure the BUSY is actually turning on. It may be happening too fast to see it.

Tried this, no luck. Bit does not get SET with the BUSY bit as trigger.

What's the version of firmware/operating system in your test PLC and the 317F-2PN/DP?

My test PLC is a 315F-2PN/DP, V3.2.3.
The 317 PLC is V3.2.11

 

[sigmadelta]

Do you think you can try updating the firmware to V3.2.12 in the CPU 317F-2 PN/DP?

https://support.industry.siemens.com/cs/document/40945128/operating-system-updates-for-cpu-317f-2-pn-dp-(6es7317-2fk14-0ab0)?dti=0&lc=en-WW

 

[JockeData]

Do you think you can try updating the firmware to V3.2.12 in the CPU 317F-2 PN/DP?

https://support.industry.siemens.com/cs/document/40945128/operating-system-updates-for-cpu-317f-2-pn-dp-(6es7317-2fk14-0ab0)?dti=0&lc=en-WW

I could probably give this a try tomorrow.

 

[Pete.S.]

Looks like the same problem but my german is a bit rusty.

http://www.sps-forum.de/simatic/40935-fehler-bei-sfc83-read_dbl.html

Looks like it has something to do with the DB changing while the SFC is in progress...I think....

.