Thanks John, We had some hall sensors that were placed properly on the PCB but when we imported the Pick and place files into solid edge to create a 3D model and mechanical check the halls we not placed correctly. It turns out that because of the part rotation on the PCB, protels calculated generated mid x,y was different than my ref x,y (which is the center of the part).
Tim -----Original Message----- From: John A. Ross [Design] [mailto:[EMAIL PROTECTED] Sent: Monday, August 25, 2003 1:47 PM To: Protel EDA Forum Subject: Re: [PEDA] Geometric Center > -----Original Message----- > From: Tim Fifield [mailto:[EMAIL PROTECTED] > Sent: Monday, August 25, 2003 4:28 PM > To: Protel EDA Forum > Subject: [PEDA] Geometric Center > > > Does anybody know how Protel 99SE calculates the geometric > center (Mid x,y) in the pick and place files? Tim As far as I am aware the midx, midy co-ordinates are a re-calculated 'center' based on a boundary box around the extremities of the electrical primitives for that part. Same way as the center is calculated within the lib editor when you ask it to set the component origin at 'center' You can see the difference in the placement files, as components with the origin already set as center in the library will have matching values in the fields midx,midy & refx,refy, but parts with the origin set at say pin 1, will have offset values in these fields. Hence the reason parts like D2PAK/TO252/263 parts usually need a 'tweaked' offset in the library so that you can use the refx,refy values in preference to the midx,midy ones. If you use library parts with correctly set origins (mostly center is fine) then you may find that the refx,refy columns are better to use than the midx,midy ones. Also watch the rotation values as they can cause some issues with post processors for placement machines with their use of 0/360 deg values which on some machines I have seen resulting in unnecessary head rotations causing quite a delay on some multi head placement machines. The rotation info is also handled worse if the library part orientation is not already matched up with the part rotation as it rests in the feeder pocket. Still never figured out why it was names pick & place output as the file contains no pick relevant information at all... Hope this helps in some way. Best Regards John A. Ross RSD Communications ltd Email [EMAIL PROTECTED] WWW http://www.rsd.tv ================================== * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * To post a message: mailto:[EMAIL PROTECTED] * * To leave this list visit: * http://www.techservinc.com/protelusers/leave.html * * Contact the list manager: * mailto:[EMAIL PROTECTED] * * Forum Guidelines Rules: * http://www.techservinc.com/protelusers/forumrules.html * * Browse or Search previous postings: * http://www.mail-archive.com/[EMAIL PROTECTED] * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
