Allen Bradley PLC5 - compute instruction

[EICS]

I am using a legacy Allen Bradley PLC5/40E Series F CPU
Having issue with compute instruction syntax with the expression
Doing a divide by floating variables for example

Destination F22:10

Expression (N7:10 *10) / F22:11

Of course I can use a divide instruction afterwards but wondering why
This instruction cannot accept divide at all?


i can seem to put a few functions in the expression but nothing using Divide? is the "/" symbol for divide not supported or some other syntax issue ?

 

[EICS]

Cancel request, I just found that divide is a "|" vertical bar symbol not a forward slash "/".

https://www.google.com.au/url?sa=t&...FjAAegQIAxAC&usg=AOvVaw3_szZlTNDa1A110c7LtKO3

 

[Ken Moore]

For future reference: CMP is on page 3-3

https://literature.rockwellautomation.com/idc/groups/literature/documents/rm/1785-rm001_-en-p.pdf

 

[EICS]

Thanks Ken, 4-5 CPT is what I'm using

 

[Operaghost]

And just as a bit of background for others that may be confused by this...

In the PLC-5 and the SLC 500, Allen-Bradley used the "/" to separate the bit from the rest of a word in an address. They referred to it as a bit delimiter. If the word was N7:0 and you wanted bit #5 then it became N7:0/5. Bit #5 in word 0 of the N7 file.

They used the "." (period) as a word delimiter. If you wanted the Preset value on a timer you might have something like T4:0.PRE since the PRE was a value (word) But if you wanted the Done bit, it would be T4:0/DN.

In the software you could always type "." and it would change it to a "/" when appropriate.

That is why they had to use the "|" pipe symbol for divide for any instruction that used an expression (CPT/CMP/FAL). Otherwise, it would have interpreted a "/" as a bit delimiter and given an error.

In the Logix 5000 they only use the "." as a delimiter so in an expression you can use the proper divide symbol.

OG

 

[drbitboy]

And just as a bit of background for others that may be confused by this...

Thanks!

 

[I_Automation]

And just as a bit of background for others that may be confused by this...

Now why would anyone ever be confused opening Rockwell software?

 

[drbitboy]

Now why would anyone ever be confused opening Rockwell software?

+1