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CAD Control diagrams

Hi,

I'm looking for information, web tutorials, books, or any other resources on how to CAD control diagrams. Searching the web has led me to advertisements time after time.

Two specific questions I have at this time:

Say I have a junction box and there is a wire from sheet 2 line 12 coming into this junction box. So this wire is numbered 2120. Now I have sheet 4 for the terminal strip in the junction box itself. Say

2120 connects to the terminal on line 5. I am showing this wire going out from 4050, but it originated at 2120. Should I continue calling the wire 2120 but show 4050 in a circle so that I can keep track of where the wire initially came from AND where it was last connected? Or should I change the wire name (when I say wire name I am referring to the number that is printed above the wire) to be 4050 in this case, since that is the last point at which the wire was connected?

One other situation I am confused about:

Say I have a connector and I am drawing the page for it. If I have two wires jumped together connected to this wire, how should I handle this? I have never seen a wire named with two numbers (i.e. 7270 / 7290), so I am guessing that I'd have to use a new name and show the jumpering on the sheet that the connection originated from?

I would like to learn how to handle both of these situations properly. I'm sure my vocabulary here is a pain to read too, so I hope to read some replies to improve upon that as well.

Thanks,

David.

Reply to
davidd31415
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In some worlds, jumpers are shown as zero-ohm resistors so there is a "component" separating the "wires" you are talking about. This is done particularly when you might have "DNI" attached to the resistor (jumper) i.e. Do Not Install - common in printed circuit board assembly.

Fred

Reply to
Fred Marshall

"davidd31415" wrote in news: snipped-for-privacy@f14g2000cwb.googlegroups.com:

If you are doing it in that manner, the wire number should change to reflect the number at last connection. Look at it this way.. Say you are the guy 3 years down the road trying to troubleshoot that wire. In the cabinet, field, etc, the wire will be labeled the same as your print. So the guy/gal reading your print, should be able to see at the component end, a wire number. Following that, it goes to some junction box with a terminal strip with 100 wires on each side. When he gets to the the terminal strip, he knows that wire 4050 is coming FROM his component, and 2120 is going backward TOWARD the control (origination point). If you do not change the wire number, some tech many not even notice that the terminal strip is there, since the wire is numbered 2120 at the device, and he/she has a 2120 at, say the PLC. May look fine at the PLC, but the problem may lie at the junction box. (Just an example.)

You don't have to use a new name, you can use ONE of the names of the two wires. In effect, if you have wire 1112 and 1113 jumpered together, then on the origination sheet, you would show the connection of the two. One of the two continues on to whereever sort of like below.

1112 o------?-------- o------| 1113

(Just my opinion..and from experience)

Reply to
Anthony

I understand what you are saying regarding future confusion if wire numbers are not changed and junction boxes are omitted. I was recently working on a system that had a print written exactly that way...

So it would be acceptable to have a wire coming up to a terminal strip with one number and have the wire connected to the other side of the terminal strip take on a new number (the same number that is written on the label for the terminal strip) ?

I guess I've just seen the same two numbers connected together on terminal strips so many times that the idea seems a bit awkward at first.

Thanks Anthony,

David

Reply to
davidd31415

"davidd31415" wrote in news: snipped-for-privacy@g43g2000cwa.googlegroups.com:

Zackly....

I feel this produces much less confusion when troubleshooting. A terminal strip is just that...a wire terminal, a place where a wire ends, hence the number should end there also, IMHO. As long as the terminal strip is labled, and the wires labeled, some technician will thank you in the future.

Reply to
Anthony

How about representing RS232c connectors on diagrams such as these? Since there are two rows of pins should I just use a square going doen the columns and show each pin on a separate line? If anyone could point me to examples (any format) I'd appreciate it.

Thanks,

David.

Anth> "davidd31415" wrote in

Reply to
davidd31415

I see a lot of different styles used in electrical prints, but there must be some educational material out there somewhere? I haven't had much luck with websites but how about books? Are there any books that cover these types of prints? Maybe I just don't have the right keyword to use to search with... Ladder-logic, control, electrical prints,...

davidd31415 wrote:

Reply to
davidd31415

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