UP COUNTER PROGRAMMED IN SIMATIC MANAGER WITH HMI

Hello Donzy;

You are using a S_CU counter, which was introduced early in the Step 7 software, and was based on S5 counter technology. You are right, PV and CV for this instruction were cded in BCD and could not exceed a value of (BCD)0999. 

To answer the frustration of many (most) Step7 programmers, Siemens introduced new timer and counter functions, based on IEC 61131-3 standards, that you will find in the IEC functions library of Step 7 instructions. SFB0, "CTU", actually uses register of type INT for the PV and the CV , so they will reach a max. of 32767.

The screenshot below shows the description of SFB0 "CTU" from the Standard and System Functions manual for S7-300 and S7-400; you can also have a look at all the new timer (SFB3 TP, SFB4 TON, SFB5 TOF) and counters (SFB0 CTU, SFB1 CTD, SFB2 CTUD) in the IEC Functions library.

https://support.industry.siemens.com/cs/ca/en/view/109751826

Please check how the Q output reacts to the values in CV and PV, it is different than the instruction S_CU that you are using now.

Hope this helps,

Daniel Chartier

Hello Donzy;

If you plan on modernizing your programming software, by all means consider TIA Portal v17. There is a bit if a learning curve to adjust to the new environment, and there are numerous licensed options you have to consider, as described in this document:

https://support.industry.siemens.com/cs/ca/en/view/109784438

Step 7 v17 Professional will allow you to program the newer S7-1200 and S7-1500  along with your S7-300 and S7-400. Select the version of WinCC v17 depending on the family of HMI or PC Runtime you decide to use. Trial versions are described at the end of the mentionned document.

On the other hand, Step 7 classic, aka Simatic Manager, is still available, and has been upgraded to Step 7 v5.7  if you choose to remain with your S7-400  and S7-300 CPUs.

The trial versions of Step 7(v5.7 and v17) are  freely downloadable , fully functional for 21 days (after which a license is required).the trial version for Step 7 v5.7 can be found here  if you woikd lje to try it out:

https://support.industry.siemens.com/cs/ca/en/view/109796156

Hope this helps, 

Daniel Chartier