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« on: December 31, 2015, 09:01:20 PM »
Hi Swarfster ,
Glad you've got it working OK - Archie really has done a great job in developing AHMI and making it so simple to get started with .
Do you need the B21 file ? Whilst you are still learning and for small programs - no . However I suggested the exclusive use of input and output files for connection to the HMI because as you learn and create bigger HMI programs with many lights , buttons and analog it becomes hard to work out where your PLC gets data from and also what apparently unconnected OTE or OTL instructions are for .
In fact I tend to use 2 larger integer files ( N files ) to handle both bit and word transfers to/from the HMI . I also tend to have 1 or 2 sub-routines in the PLC exclusively for HMI interfacing . Believe me - it is tedious going back to a program after a couple of years if you don't . But bear in mind there are several different ways to program PLCs and HMIs - its just working out whats best for a particular solution .
Physical inputs can of course be placed in parallel with HMI inputs and steering logic to select which is used . For example , you might have automatic operation of equipment from the PLC and manual operation from the HMI for testing etc. with a select switch choosing which mode or you could do it from the HMI with a keypad used for entering a manual mode password .
There are several demonstations of AHMI on U-Tube and also some of the posts on this forum should also be very useful to you .
Good luck as you learn and also a Happy New Year to you .
Paul