Fire alarm system - Creating custom Blocks and extracting data from those blocks.

[jkendrick]

I produce shop drawings for installation and approval by the authorities having jurisdiction of mainly commercial fire alarm systems.

I've played with customization as I've watched Autocad evolve over the past decade and I've got a good idea of what autocad could do but I just don't know how to do it. I'm sure somone has done what I want to do so I come to y'all. I hope these aren't complete noob questions.

I pretty good at modifying apps I've found for free on the net (lisp's, etc.) so if any of you Gurus could possibly point me in the right direction to get me started I'll probably live longer.

I really only have two basic needs, counting devices/cables and from that info calculate battery requirements and voltage drop. I know how to extract attributes from blocks and I think that's where I need to start but my first problem is this:

1. How can I extract attributes from blocks across multiple drawings into a table? I put one floor or partial floor per drawing but how can I get all the blocks from the whole job into one count? I can extract the info into a bill of materials for each drawing, which I need anyway, but I also want to have a master BOM on a legend sheet with the totals from all the sheets that will update automatically or on demand as revisions are made. Once I get over that hurdle the rest is downhill...

2. Blocks for multi-part devices. For example, I use a rectangle with "FACP" as my block for a fire alarm control panel, but that panel consists of several parts, CPU, cabinet, batteries, expansion modules, etc. I'd like to have each part as a line item next to the one FACP symbol.

3. Counting conduits and cables. Currently I use polylines to indicate conduit and a dimension quick leader to lable it's size and the types and quantities of cables within,
e.g.:

3/4" EMT, 1A, 4B, 2C

I like the leader because it moves with the text, and space gets tight often. Can I insert a block on a leader to annotate those attributes (I believe it's called a tag or balloon?) for raceway size, raceway type, raceway length, and quantities of each type of cable then extract that info into a BOM/cable schedule?

4. Battery/Voltage drop calculations. Fire alarm systems are required to run on batteries upon loss of AC power for a certain amount of time. This is a simple math problem and I've read that tables can do formulas. Can I extract the attributes for all the devices on a panel into a table that will do the math for me automatically? Voltage drop calcs are a function of wire distance and device current draw and would be similar but for each circuit on a panel. Can I take the length of a conduit run and the current draw of a device and have the table keep a running total of what the voltage will be at each device? I guess what I want to do is use attributes from blocks in formulas within the cell of a table? Can this be done?

So can AutoCAD do these things or am I even using the right program for what I want to do?

[thomas.stright]

Looks like Dynamic Blocks and Tables can solve alot of this for you.....

[David.Hoole]

Take a look at the EATTEXT command in detail. It will do much of what you're looking for. It can handle multiple drawing files, nested blocks, and blocks in external references.

It will output the data in a number of useful formats, including an Autocad Table.

Be wary of using formulas in the table itself. Formulas must be added to the table manually and are destroyed when the table is updated!! One possible work-around is to place the formulas in a seperate table which references cells in the automated table. However, the link must be input manually (no picking allowed) and the syntax is far from user-friendly!

You can indeed attach a block to a leader. Take a look at the Leader>Annotation>Block option, or the Qleader>Settings dialogue.

Depending on the level of sophistication you're looking for, and the weight of your wallet, you might be best advised to look at some of the 3rd Party/Autodesk vertical apps which are available for electrical engineering. My background is structural, so I can't advise on specific products.

[macwizzy06]

Hi Dave, your suggestion seems very interesting but i'm a bit at a loss on how to. A few times, i've had to make Fire Alarm drawings and faced similar problems with aligning total detectors on all floors, adding/removing data on existing blocks, etc

Could you post a descriptive file showing screen shots, please? This could go a long way.