#1 for James response, I would like to add a bit as well, it appears you will not be doing any real world programming at the moment and as you seem to have no real I/O. Many people like to simulate their program before going to site, this can make a huge difference even on a small one.
Follow the above and put all Inputs into a separate program block and map them into internal bits, do the same for the outputs i.e. map the internal bits to the real outputs but do not call these blocks, this way the PLC will not complain about I/O that does not exist (Before anyone comments I know you can disable this on the I/O racks). Give the mapped bits for the I/O a name similar to that of the Real I/O i.e. Input O:0/0 is PX01_V001_Open Map this into a bit say B3:0/0 And Call it PX01_V001_Open_M (use say M to show it is mapped) and use the mapped I/O in the programs you create. This way you can simulate without real I/O You can also write other blocks of code to simulate real world situations and call these during simulation and remove them for site installation.
For example you have a valve with one output and two inputs for the limits so in the simulation blocks you can simulate a valve opening & closing by using the not output starting a timer then the timer switches on the mapped input for valve closed and then do the same for the open limit by using the mapped output to turn on the Open mapped bit.
You can simulate tanks filling and emptying with the simulation logic etc.
As already mentioned, document well, structure your programs think about the way you intend to structure the code.
Follow the above and put all Inputs into a separate program block and map them into internal bits, do the same for the outputs i.e. map the internal bits to the real outputs but do not call these blocks, this way the PLC will not complain about I/O that does not exist (Before anyone comments I know you can disable this on the I/O racks). Give the mapped bits for the I/O a name similar to that of the Real I/O i.e. Input O:0/0 is PX01_V001_Open Map this into a bit say B3:0/0 And Call it PX01_V001_Open_M (use say M to show it is mapped) and use the mapped I/O in the programs you create. This way you can simulate without real I/O You can also write other blocks of code to simulate real world situations and call these during simulation and remove them for site installation.
For example you have a valve with one output and two inputs for the limits so in the simulation blocks you can simulate a valve opening & closing by using the not output starting a timer then the timer switches on the mapped input for valve closed and then do the same for the open limit by using the mapped output to turn on the Open mapped bit.
You can simulate tanks filling and emptying with the simulation logic etc.
As already mentioned, document well, structure your programs think about the way you intend to structure the code.
