GerryB55

SET and RST will work but you must remember that if your SFC program branches after the SET you may need several RST commands. I use blocks to do the sequence logic then drive my outputs in a seperate block. You can either use M coils in the main SFC steps or the BLm/Sn command, to drive the coil when the particular steps are called. This is particularily useful if you are calling the output from different blocks. Hope this helps.

I'm working on a spreadsheet to estimate costs. In the past I have used a 'best guess' for estimating the actual PLC and HMI programming times. Does anyone have any ideas, or know where I might get some, on estimating times based on I/O count, number of modules, tags, number of screens etc? Any ideas gratfully recieved. Thanks in advance

Problem solved: I wanted to goto step 0 from within a step not by a transistion, mainly to keep the SFC diagram smaller and neat. The command SCHG K#, where # is the step to goto, in a step goes to the step AND deactivates that step. Thanks for all advice.

Problem solved: I had inadvertantly overlapped the data registers for the PID initialisation and the PID loop data. Moving the start registers cured the problem and all are up and running now. Thanks for all help.

Waynes Hi, i've tried the examples but seem to be having problems. PLC reports a conflict of some sort in the data types. I would appreciate any known working examples you may have. Gerry

Hi I am writing a program using SFC on a Q02 PLC. Under certain conditions the program goes to Step 0 of the block. I need a command for use in this Step which will ensure that ALL other steps in the block are reset. On the FX etc I would use the ZRST function. Any ideas please?

I am using a Q02 PLC part of which needs to control a Heat / Cool system. Can anyone help with advice on setting up and controlling the outputs. Specifically do I use seperate PID loops for Heat & Cool? Thanks in advance.