Using SFB47 & the COUNTVAL to compare values

I am using a 313C & the HSC for positioning & controlling of a robot arm.

But when I try to stop the arm at a certain location using a comparator, it does't stop at that point.  It is almost as though the HSC is too fast for the compare instruction to read it.

Can anybody give any advice on how to control the arm based on certain coordinates that I have set?

Thanks.

Hi, 

Do you use HW interrupt to handle your counter? See SIMATIC S7-300 CPU 31xC Technological Functions  under chapter "5.5.12 Hardware Interrupt during Count Operation" for information.

I hope I could help!

 Thanks for the reply.

No I don't used the HW interrupt.  I have had a look through that manual, but didn't think the HW interrupt would do what I wanted.

Would this allow me to stop the arm at different locations?

MicroMan

Hi, 

Do you use HW interrupt to handle your counter? See SIMATIC S7-300 CPU 31xC Technological Functions  under chapter "5.5.12 Hardware Interrupt during Count Operation" for information.

I hope I could help!

Hi,

1. The SIMATIC S7-300 CPU 31xC Technological Functions manual introduce the intended functionality in chapter "2.4 Components for Positioning Control". 
2. Have you considered to use proximity switches and HW interrupts on a suitable DI card? See the What is a hardware interrupt and how do they work in the S7-300 system?
3. The question regarding to setting up HW interrupt for a multiple compare value? Tricky, nothing I have tried. If you see What is a hardware interrupt and how do they work in the S7-300 system?, you can read:
   "Configuring hardware interrupt modules:The modules with hardware interrupt capability can also be configured during an ongoing program cycle by means of system functions SFC 55 (WR_PARM), SFC 56 (WR_DPARM) and SFC57 (PARM_MOD). You can find out how to configure the corresponding data records with the system functions in the manual "Programmable Logic Controller S7-300 Module Data" in Entry ID:8859629."
   Keep in mind the execution/comms time of these SFC's.
   
   
   Keep us posted!