Hi All,
This may seem like a simple question, but as i have a mechanical background,things like following always seem to trip me up!
Ok - We have an old Hydraulic press which is being refurbished to use on a new project. The electrical control currently is Relay Logic, the usual problematic relay issues have swayed my boss to replace this with PLC controls (Siemens S7).
Currently the parts are loaded, the operator presses the start button momentarily and providing the Lightguards(Sick) are clear - The cycle runs.
First Question:
Where can i find or is there a calculation for the distance for the lightguard position with relation to the moving ram? I want to check this as it just looks to close!
Second Question:
The start button has a N/O & N/C contact which is interlocked using relays(Not safety type) i.e one makes/one breaks to monitor correct operation.
I dont like the idea of a one handed start even though the work area is protected by Lightguards, However that feature must stay according to my boss! How would you update this PLC wise?
I was thinking of using just a single N/O contact to a PLC Input,and then monitoring the rising edge to protect against sticking contacts, Plus a timed supervision if exceeded fires a Alarm Message (Contact Error - Start Button etc).
Hope my ramblings make sense, and thanks for any advice offered
STL
This may seem like a simple question, but as i have a mechanical background,things like following always seem to trip me up!
Ok - We have an old Hydraulic press which is being refurbished to use on a new project. The electrical control currently is Relay Logic, the usual problematic relay issues have swayed my boss to replace this with PLC controls (Siemens S7).
Currently the parts are loaded, the operator presses the start button momentarily and providing the Lightguards(Sick) are clear - The cycle runs.
First Question:
Where can i find or is there a calculation for the distance for the lightguard position with relation to the moving ram? I want to check this as it just looks to close!
Second Question:
The start button has a N/O & N/C contact which is interlocked using relays(Not safety type) i.e one makes/one breaks to monitor correct operation.
I dont like the idea of a one handed start even though the work area is protected by Lightguards, However that feature must stay according to my boss! How would you update this PLC wise?
I was thinking of using just a single N/O contact to a PLC Input,and then monitoring the rising edge to protect against sticking contacts, Plus a timed supervision if exceeded fires a Alarm Message (Contact Error - Start Button etc).
Hope my ramblings make sense, and thanks for any advice offered
STL