Omron CQM1 CPU21 & FTView SE

Hi All,

I am using the OMRON CQM1 CPU21 to measure the machine downtime and do some calculation and display in the FactoryTalk View SE (Computer) as well as allow user to key in some data from the FactoryTalk View SE. However, the FactoryTalk View SE were not able to display the exact value that get from the OMRON CQM1 CPU21 as well as the OMRON CQM1 CPU21 were not able to get the data that key in from the FactoryTalk View SE. Data in the OMRON CQM1 CPU21 is in BCD data type, the numeric display and numeric input in FactoryTalk View SE are in Integer. But, I had try different data type (numeric display & input) in FactoryTalk View SE, and it is still not successful to display and key in. May I know what is the problem that cause it?

Thank you.

Are your communication tags in the tag dictionary?
Have you selected the datatype to be "4-Digit BCD" in FTView?
What is the actual number you see in the PLC, and then the number you see in FTView?

If "Actual" is 1234, and you see 3412, or some other combination, you will need to configure your IO server in some way to reorder the bytes, or do it by hand in the PLC.

The issue you are likely seeing is what you've already stated: the CQM1 uses BCD.

BCD stands for Binary Coded Decimal. Each digit in a BCD number is represented by four bits. So, the the BCD number 1234:

You can see where things will go awry in a hurry.

Try converting your BCD number to an binary number (using the BIN function) and see what your results are.

Good luck!

EDIT: @rdrast and I are attacking the problem from two directions!

rdrast said:

Are your communication tags in the tag dictionary?
Have you selected the datatype to be "4-Digit BCD" in FTView?
What is the actual number you see in the PLC, and then the number you see in FTView?

If "Actual" is 1234, and you see 3412, or some other combination, you will need to configure your IO server in some way to reorder the bytes, or do it by hand in the PLC.

Click to expand...

yes, I have assigned communication tags (tag from kepserver) in the FTView tag dictionary. Datatype is also selected as "4-Digit BCD" in FTView. I have key in 20 in FTView, but PLC got 32. Numeric display doesn't display anything. Do I need to assign the datatype in the kepserver? Originally is in Word datatype, but i had change to BCD datatype. Thanks for the help.

rdrast said:

Are your communication tags in the tag dictionary?
Have you selected the datatype to be "4-Digit BCD" in FTView?
What is the actual number you see in the PLC, and then the number you see in FTView?

If "Actual" is 1234, and you see 3412, or some other combination, you will need to configure your IO server in some way to reorder the bytes, or do it by hand in the PLC.

Click to expand...

JordanCClark said:

The issue you are likely seeing is what you've already stated: the CQM1 uses BCD.

BCD stands for Binary Coded Decimal. Each digit in a BCD number is represented by four bits. So, the the BCD number 1234:

Code:

BCD:     |  1   |  2   |  3   |  4   |
Binary:  | 0001 | 0010 | 0011 | 0100 |

0001001000110100 binary = 4660 decimal

You can see where things will go awry in a hurry.

Try converting your BCD number to an binary number (using the BIN function) and see what your results are.

Good luck!

EDIT: @rdrast and I are attacking the problem from two directions!

Click to expand...

Thanks for the help

Cwz90 said:

yes, I have assigned communication tags (tag from kepserver) in the FTView tag dictionary. Datatype is also selected as "4-Digit BCD" in FTView. I have key in 20 in FTView, but PLC got 32. Numeric display doesn't display anything. Do I need to assign the datatype in the kepserver? Originally is in Word datatype, but i had change to BCD datatype. Thanks for the help.

Click to expand...

If you change data types in kepserver, you may need to reinitialize it. I have seen that if something was already connected to the opc tag, it will keep using the original datatype until it's restarted.