Isn't there a standard FC in the Siemens library to decode this 4 number BCD code switch?

Dear Support,

I would like to connect a BCD code switch and a BCD display to a Siemens S7 PLC. Firstly I would like to see on the BCD display, what I set up on the BCD code switch. I have a few questions regarding this setup.

- CPU: 317F - 2PN/DP (317-2FK14-0AB0)

- I/O card: SM 323 DI/DO 16xDC24V (323-1BL00-0AA0)

- BCD code switch: Flush-mounted encoding switch BCD compl.- SMC-D-137-AK-2 (Material Number from Distrelec: 135-80-644).This is connected from I8.0

- BCD Display: KINGBRIGHT CC56-12EWA M. This is connected from Q8.0.

First of all, regarding the BCD code switch. Isn't there a standard FC in the Siemens library to decode this 4 number BCD code switch? I needed to wrote down the truth table of it in LAD to be able to see in the program what I set up on the BCD code switch (see in attachment FC3). BCD to integer did not work for me. 

[snip]

I hope you can help me. 

Best regards,

Tibor

Hello Tibor,

First question

for the S7-1200/1500 are there functions at the LGF (Library of general functions).

At the S7-300 I would do the follow

• first (lowest) digit (0..9) is connect to the in .0 to .3
• second digit (0X..9X) is connected to .4 to .7
• read the input byte
• mask your byte with W#16#0F
  (with AND)
  the result is the number in INT for the first digit (lowest number)
• read the input byte
  
• shift this byte for 4 places to right (shift word to right)
  
• then you have the second digit as a INT
• multiply this value with 10
• add the first and the second value
• ..... also for the next digits (3 (100) and 4 (1000))

[snip]

Hope this is a little bit helpful.

regards
CaOd

New question published by AutoGen_4087331 is split to a separate thread with the subject Can the FC93 standard libary work with this type of BCD display?.

Best regards
Jen_Moderator