R
<clip>
Can anyone name a successfully marketed PLC that does not run ladder logic?
</clip>
<clip>
modern PLC's do support some other style of programming, but the common
ground they all meet on is ladder logic.
</clip>
PLC's and automation controllers not on ladder. Also, are we talking about PLCs here or Automation Controllers ?
I have seen several (as already pointed out over the years) -- tools such
as:
- APT (Siemens SIMATIC from TI)
- STEP 7 (Siemens from Germany)
- QuickStep (Our good hosts at Control.com)
- ....
OK APT compiles down to (sort of) ladder logic -- fun to follow in TISOFT anyway. The QuickStep controller does not use ladder at all and Siemens are certainly no fans of ladder either. As far as I am aware, the base language of the S5/S7 is not ladder logic. I do not feel that ladder logic is a good common ground for processors. I feel that the common ground for automation
controllers should be an assembler language (instruction list) that can be represented in ladder logic or structured text with little or no difficulty by a higher layer of the application.
How does a modern automation controller with scheduled tasks and so on really run under easy-to-follow ladder? A modern system is not a "single scan" application. A SLC5 with only a limited number of interrupt based routines is hardly useful when you want the OS of the controller to handle tasks that run at 1ms, 5ms, 10ms (and so on) intervals -- that is without
writing a ton of ladder yourself.
I may not like writing simple Boolean tasks in APT, but you cannot beat the Pascal-like syntax for higher level stuff that customers expect in their machines.
It is unfortunate that APT has been somewhat marginalised by the passing of time ... I am about to delve for the first time into Siemens PCS-7 with STEP-7 -- no mention of ladder logic in the Siemens manuals I have read so far.
RJ
Ranjan Acharya
905-634-0844 x 238 (V)
Team Leader - Systems Group
905-634-9548 (F)
Grantek Control Systems http://www.grantek.com/
[email protected]
[email protected]
_______________________________________________
LinuxPLC mailing list
[email protected]
http://linuxplc.org/mailman/listinfo/linuxplc
Can anyone name a successfully marketed PLC that does not run ladder logic?
</clip>
<clip>
modern PLC's do support some other style of programming, but the common
ground they all meet on is ladder logic.
</clip>
PLC's and automation controllers not on ladder. Also, are we talking about PLCs here or Automation Controllers ?
I have seen several (as already pointed out over the years) -- tools such
as:
- APT (Siemens SIMATIC from TI)
- STEP 7 (Siemens from Germany)
- QuickStep (Our good hosts at Control.com)
- ....
OK APT compiles down to (sort of) ladder logic -- fun to follow in TISOFT anyway. The QuickStep controller does not use ladder at all and Siemens are certainly no fans of ladder either. As far as I am aware, the base language of the S5/S7 is not ladder logic. I do not feel that ladder logic is a good common ground for processors. I feel that the common ground for automation
controllers should be an assembler language (instruction list) that can be represented in ladder logic or structured text with little or no difficulty by a higher layer of the application.
How does a modern automation controller with scheduled tasks and so on really run under easy-to-follow ladder? A modern system is not a "single scan" application. A SLC5 with only a limited number of interrupt based routines is hardly useful when you want the OS of the controller to handle tasks that run at 1ms, 5ms, 10ms (and so on) intervals -- that is without
writing a ton of ladder yourself.
I may not like writing simple Boolean tasks in APT, but you cannot beat the Pascal-like syntax for higher level stuff that customers expect in their machines.
It is unfortunate that APT has been somewhat marginalised by the passing of time ... I am about to delve for the first time into Siemens PCS-7 with STEP-7 -- no mention of ladder logic in the Siemens manuals I have read so far.
RJ
Ranjan Acharya
905-634-0844 x 238 (V)
Team Leader - Systems Group
905-634-9548 (F)
Grantek Control Systems http://www.grantek.com/
[email protected]
[email protected]
_______________________________________________
LinuxPLC mailing list
[email protected]
http://linuxplc.org/mailman/listinfo/linuxplc