CX 100
The CX 100[note 1] is an all-relay switch manufactured by North Electric. It can support up to 100 individual lines which can theoretically connect up to 1000 subscribers if party lines are used. It has space for up to 10 links, or sets of line finders plus connectors.
Architecture
The CX 100 is designed with principles familiar to step-by-step switches. Line finders find which phone is taken off hook, and connectors are used to make the final connection to desired subscriber lines. Since it only concerns 100 lines, line finders are attached directly to connectors in circuits called links, and only tens and ones are tracked.
Four digits are supported with the option to swallow leading digits to simulate an office code. The digits have the following purposes in order:
- Select a group of subscribers to call (only one group exists in the case of the CX 100) or select a trunk
- Tens digit of desired subscriber
- Ones digit of desired subscriber
- Ringing code to be sent to all party members on the line
Notes
- ↑ There is disagreement among various references including North Electric's own marketing material on whether the name CX 100, CX-100, or CX100 should be used. However, CX 100 is the most common name used by North Electric and therefore the name accepted by the museum.