input edge

[dwpang]

hi anyone can help to explain the meaning of input edge? or how does the input edge occur? the attach pic explains more. thanks.

 

[RheinhardtP]

Input terminal on the unit. What type of device is this?

 

[dwpang]

hi thanks rhein. its twido software. using schneider electric plc. so input edge basically means a input terminal?

 

[LadderLogic]

I think 'input transition' would make a better choice of words here than 'input edge'. A transition, change of state from something to something else.

 

[dwpang]

ok.. i still dont quite get it. so as seen from the attached pic, %sw58 occurs when blackout happens right, and the reason is because of this input edge or input transition. so any examples of what can cause this to happen? thanks.

 

[Eric Nelson]

I just had a look through the manual (LINK), and on page 463, there is a setting to use a run/stop input.

Maybe your PLC is set up to use an external run/stop command (relay, switch, etc.)?

If it is, then I'm thinking when that input turns off, it will stick a "1" in %SW58.

Some PLCs (DL405 for example) have a connection for an external 'run' contact. This may be something like that.



-Eric

 

[dwpang]

oh i understand now. thanks guys!