Cable numbering

Numbering is a subject more likely than most to divide a group of engineers. We all agree that cable numbering is essential but how to do it ? Only two points unite most people: 1) numbers must be unique, 2) the same number should be at both ends of the cable.

Here at connectCAD for a long time we’ve had some very fixed simple numbering systems offered on a take-it-or-leave-it basis. And this has always seemed a little autocratic. So finally in 2015 we’ve created a whole new numbering paradigm that lets YOU define the numbering system you want. Here it is!

Numbering systems


We set up numbering systems in the connectCAD Settings dialog. Each system has a name and a description. To use a system to number the current document, select the system in the list and click the Set as Current button.

The Add , Edit and Remove buttons do exactly what they say. Now let’s click Edit and see what a numbering system looks like inside.

Rule-based numbering


Each numbering system comprises a set of rules. Each rule has a set of match conditions plus a cable number format. When we’re numbering a circuit the rules are applied in order until one of them matches the circuit data. Then the corresponding cable number is created from the format.

The first rule to succeed is the one that creates the cable number. So when you are designing a numbering system you put the most specific rules first, then the more general ‘catch-all’ rules.

Easier to see than to explain, so let’s take a look at the first rule in more detail.

Numbering rules in detail


The match rule shown has two match conditions. Each condition takes the value of a Circuit parameter and sees if it begins with a specific prefix. For the rule to suceed both match conditions must be met.

For example, this rule looks for source device name beginning with ‘?JF_’ where ? is a wildcard matching any one character. And for the match to succeed the source socket name must begin with ‘PORT’. So what it’s doing here is searching for circuits coming from any kind of jackfield. If both match conditions are true then the number format is used to create a cable number.

The Number Format can be any fixed letters and numbers plus tags that extract data from the match rule. In this case we have three tags:

  • %s which means “insert the signal type letter”
  • #1 take the source device name suffix after match, and convert it to a number
  • #2 take the source socket name suffix after match, and convert it to a number

So in this case say for VJF_A, PORT02 this rule would generate a cable number V0102

More about numbering rules


Numbering rules are in fact text sentences in our special numbering language. Here’s a breakdown of how that language works:


^ means “begins with” so each match condition is defined as <parameter value> begins with <match string>

& means a logical AND joining up match conditions. So the rule succeeds when <match1>&<match2> is TRUE

= means IF matches succeed THEN generate using this format

The numbering rule editor lets you create most normal kinds of rules, but if you need to create something special you can use the text editor to create custom rules using any Circuit parameters and several match conditions.

Numbering formats explained


Here is a flow diagram of the entire numbering process. Circuit parameters are compared to match strings and if all the matches succeed then the number format is used to create a cable number for the circuit. So let’s look at the number format more closely.

Number formats are text strings with special tags in them. Any text that isn’t a tag goes straight into the cable number as is. So for example:

Format Cable number
hello hello
9000 9000

Tags get replaced by their current value. These tags are available in connectCAD.

Tag Value
?1 wildcard matches from condition 1 as a string
?2 wildcard matches from condition 2 as a string
%1 suffix from condition 1 after match string is removed
%2 suffix from condition 2 after match string is removed
#1 suffix from condition 1 after match string is removed converted to number
#2 suffix from condition 2 after match string is removed converted to number
%s signal type letter for circuit signal type
%g unique number generator ( 1 char )
%gg unique number generator ( 2 char )
%ggg unique number generator ( 3 char ) etc..

More examples

Format Extracted text 1 Extracted text 2 Cable number
8#1#2 A 2 8012
8%1%2 A 2 8A2
9%ggg <any> <any> 9001 ( whatever 3 numbers give a unique cable number )

Conversion to numbers is done using the labelling character sequence that is defined in connectCAD Settings. This way jackfield labels are accurately converted their numeric equivalent for any labelling system.


Having more flexibility comes at a price. You get to experience more of the complexity. But we do feel that this new numbering paradigm is more in line with the overall philosophy of connectCAD – to put the power in your hands.

Like any new development we fully expect to have to make some changes, and we’d welcome your feedback.

One thought on “Cable numbering”

  1. Hello,

    I’ve been editing number formats but I can’t seem to come up with a format that will number cables in a way that will display the devices it is connected to. For example, if I want a cable to be numbered TV-101-001 when it is the 1st cable to a device named TV-101, how would I go about doing that? That is if its possible with the current numbering settings. Thanks!

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