Ron Beaufort
Lifetime Supporting Member
Greetings Siemens people ...
first of all, I know NOTHING about Siemens - but I’d like to ask a question ... feel free to simply ignore me ...
suppose we use the program in Post #15 ...
suppose that switch M0.0 is OFF in the field ...
suppose that switch M1.0 is OFF in the field ...
suppose that the processor is powered down ...
suppose that while the processor is powered down, M0.0 and M1.0 are both turned ON in the field ... (for example: an operator manually moves a box in front of each of two proximity detectors) ...
now suppose that the processor is powered back up again ...
question A: will M0.2 give a pulse? ...
question B: will M1.2 give a pulse? ...
like I said, I know nothing about Siemens - but in an Allen-Bradley system, these questions could be food for thought ... and ... the answer MIGHT be different depending on whether we’re talking about a PLC-5, or an SLC-500, or a ControlLogix system ...
possible moral of the story: sometimes things work fine in “normal” operation - but may cause surprises when the system is powered off, or faults, etc. ...
just curious about how Siemens handles things like this when compared to Allen-Bradley ...
thank you ...
first of all, I know NOTHING about Siemens - but I’d like to ask a question ... feel free to simply ignore me ...
suppose we use the program in Post #15 ...
suppose that switch M0.0 is OFF in the field ...
suppose that switch M1.0 is OFF in the field ...
suppose that the processor is powered down ...
suppose that while the processor is powered down, M0.0 and M1.0 are both turned ON in the field ... (for example: an operator manually moves a box in front of each of two proximity detectors) ...
now suppose that the processor is powered back up again ...
question A: will M0.2 give a pulse? ...
question B: will M1.2 give a pulse? ...
like I said, I know nothing about Siemens - but in an Allen-Bradley system, these questions could be food for thought ... and ... the answer MIGHT be different depending on whether we’re talking about a PLC-5, or an SLC-500, or a ControlLogix system ...
possible moral of the story: sometimes things work fine in “normal” operation - but may cause surprises when the system is powered off, or faults, etc. ...
just curious about how Siemens handles things like this when compared to Allen-Bradley ...
thank you ...