Limit / Home Switch
- dextaca
 - Offline
 - Junior Member
 - 
				
			 
		Less
		More
		
			
	
		- Posts: 38
 - Thank you received: 0
 
			
	
						29 Dec 2016 00:16				#84825
		by dextaca
	
	
		
			
	
			
			 		
													
	
				Limit / Home Switch was created by dextaca			
			
				Gents / ladies. Just a quick one .
Any suggestion on how I could wire a 2 switch limit / home switch ( Omron limit switch VB-2121) to work with 3 wire systems ( Linux CNC) ?
Regards
Peter
					Any suggestion on how I could wire a 2 switch limit / home switch ( Omron limit switch VB-2121) to work with 3 wire systems ( Linux CNC) ?
Regards
Peter
Please Log in or Create an account to join the conversation.
- rodw
 - 
				
											 - Offline
 - Platinum Member
 - 
				
			 
		Less
		More
		
			
	
		- Posts: 11472
 - Thank you received: 3848
 
			
	
						29 Dec 2016 01:38				#84831
		by rodw
	
	
		
			
	
			
			 		
													
	
				Replied by rodw on topic Limit / Home Switch			
			
				I think one of them would be set as a shared home/limit switch and the other to operate as an independent limit switch.
linuxcnc.org/docs/html/config/ini-homing.html
Just make sure your HOME_OFFSET moves the axis far enough to clear the switch or you will get a limit error once the homing sequence is completed.
					linuxcnc.org/docs/html/config/ini-homing.html
Just make sure your HOME_OFFSET moves the axis far enough to clear the switch or you will get a limit error once the homing sequence is completed.
Please Log in or Create an account to join the conversation.
- andypugh
 - 
				
											 - Offline
 - Moderator
 - 
				
			 
		Less
		More
		
			
	
		- Posts: 19678
 - Thank you received: 4559
 
			
	
						01 Jan 2017 01:07				#84979
		by andypugh
	
	
		
			
	
			
			 		
													
	
				Replied by andypugh on topic Limit / Home Switch			
			
				I am not sure that I understand the question.
Are you saying that you have 2-wire limit switches and you want to combine them to use a single digital input?
					Are you saying that you have 2-wire limit switches and you want to combine them to use a single digital input?
Please Log in or Create an account to join the conversation.
- dextaca
 - Offline
 - Junior Member
 - 
				
			 
		Less
		More
		
			
	
		- Posts: 38
 - Thank you received: 0
 
			
	
						01 Jan 2017 12:53				#85000
		by dextaca
	
	
		
			
	
			
			 		
													
	
				Replied by dextaca on topic Limit / Home Switch			
			
				Sorry I guess my explication is a bit crude.. Fanuc 0M mills have only 2 switches (Omron limit switch VB-2121) one switch acts as a pos / neg switch ,as home switch.. Problem is that I have a new servo retrofit ( Yaskawa that needs pos / neg switch , then I need a 3rd switch or a way of sharing one limit switch as a home for LinuxCNC? Any suggestion?
Details is that if I tyake the falling edge as high.. the servopacks block and will not overtravel until low...
that's my dillema..
					Details is that if I tyake the falling edge as high.. the servopacks block and will not overtravel until low...
that's my dillema..
Please Log in or Create an account to join the conversation.
- andypugh
 - 
				
											 - Offline
 - Moderator
 - 
				
			 
		Less
		More
		
			
	
		- Posts: 19678
 - Thank you received: 4559
 
			
	
						01 Jan 2017 12:58				#85001
		by andypugh
	
	
		
			
	
			
			 		
													
	
				Replied by andypugh on topic Limit / Home Switch			
			
				It is quite usual for all home and limit switches to be entirely controlled by LinuxCNC and to not have a hardwired connection to the drives. So the simple answer might be to simply not wire the limits to the drives.
If you definitely want to retain hardware limit switches then you could consider a LinuxCNC-controlled relay to bypass the limit switch during the homing sequence.
					If you definitely want to retain hardware limit switches then you could consider a LinuxCNC-controlled relay to bypass the limit switch during the homing sequence.
Please Log in or Create an account to join the conversation.
- rodw
 - 
				
											 - Offline
 - Platinum Member
 - 
				
			 
		Less
		More
		
			
	
		- Posts: 11472
 - Thank you received: 3848
 
			
	
						01 Jan 2017 13:08				#85002
		by rodw
	
	
		
			
	
			
			 		
													
	
				Replied by rodw on topic Limit / Home Switch			
			
				If you take Andys suggestion and not wire the limits to the drives, then if you follow these instructions
linuxcnc.org/docs/html/config/ini-homing.html
You will end up with something like this in your .ini file on the axis with the shared home/limit switch
			
					linuxcnc.org/docs/html/config/ini-homing.html
You will end up with something like this in your .ini file on the axis with the shared home/limit switch
HOME_OFFSET = 0.0
HOME_SEARCH_VEL = -10 
HOME_LATCH_VEL = 5
HOME_FINAL_VEL = 10
HOME_USE_INDEX = NO
HOME_SEQUENCE = 0
HOME_IS_SHARED = 1Please Log in or Create an account to join the conversation.
		Time to create page: 0.121 seconds