E911 Compatibility of the NEC SL2100

The NEC SL2100 is compliant with Kari’s Law requirements. Here is an in-depth look of how the NEC SL2100 handles E911 calls.

E911 Compatibility ensures that emergency calls always get through. If an emergency occurs, a user goes to any telephone, lifts the handset and dials 911. The system built-in E911 Compatibility places the emergency call even if the user forgets to dial an access code or press a line key. The E911 abilities include:

Attendant Notification:
The attendant receives a notification each time a co-worker dials an emergency 911 call. This notification is the co-worker’s name and number display optionally accompanied by an audible alarm. Notification occurs regardless of whether the attendant is idle or busy on a call. You can optionally extend this ability to other supervisory extensions as well.

Emergency Routing
When an extension user dials 911, the system can automatically find a trunk for the call. The system can choose a route to which the user normally does not have access. If all normal routes are busy, the system can even disconnect an active call and place the emergency call. E911 Compatibility uses the flexibility of the Automatic Route Selection Call Route Options to route 911 emergency calls (even in systems in which ARS is not enabled).

E911 Outgoing Dialing
The E911 call follows the trunk group route programming. It is possible to use the flexibility of the Automatic Route Selection Call Route Options for additional routing options.

Forced Disconnect Follows Timer to Disconnect Call
When all lines in the programmed route are busy and the system must drop a call to place a 911 call, the system waits the time set in Program 81-01 before disconnecting the call.

Calling Party Identification
With ISDN installed, the system can provide the Calling Party Number (CPN) Presentation from Station. No additional customer-provided 911 equipment is required.

WARNING: Uninstalled Trunks in Trunk Group Will Prevent Call from Dialing Out

By system default, all trunks in Program 14-05-01 Trunk Group are in group 1. When placing a 911 call, the system tries to access the trunks defined in the group.

If the trunks do not exist, the call does not dial out.

For E911 to function correctly, remove any uninstalled trunks from the trunk group.

If Program 21-01-12 is set to 0 (trunk access code required), when using the Dial Number Preview feature and dialing 9+911, if all trunks are busy, the user hears a busy signal and the call does not dial out.

If Program 21-01-12 is set to 1 (trunk access code not required) and using Dial Number Preview, 911 is dialed, the system disconnects a trunk and dials the call.

Dial Number Preview is when a telephone number is first dialed (previewing the number in the display) then Speaker or a line key is pressed to place the call.


  • If Program 21-01-10 is programmed with an entry other than 0, a call does not have a talk path unless the user dials at least the number of digits entered in this option when placing an outgoing call.
  • This means that an entry of 4 or higher in this program causes a problem when dialing 911. Since it is only a 3-digit number, the call does not have a talk path, preventing the emergency dispatcher from hearing the caller. This option should be kept at its default setting of 0 to prevent any problem with dialing 911.
  • CAMA Trunks are not supported.
  • The 911 Cut Through feature works when dialing trunk Access+911

Important Notes

1. When ARS is NOT enabled and the system allows trunk access by dialing 9 , Single Line Terminals disregard PRG 20-03-03 (System Options for Single Lines Terminals – SLT DTMF Dial to Trunk Lines).

This prevents the system from connecting to a trunk until all the digits are dialed. This can be avoided by using either 8 or 9x (but not 91) as the trunk access code. Be aware that this change requires additional programming changes.

2. Do not use * in a PBX access code if the Account Code feature is used. With the Account Code feature enabled, if this is used in the access code, the trunk stops sending digits to the central office after the * is sent.

3. Finally, but most importantly, TEST – TEST – TEST!! Due to the nature of the E911 feature, it is imperative that when programming this, or any other feature, to be aware of the consequences. Make sure to test the extensions with the E911 feature to confirm that other features do not prevent the call from being completed. When using external equipment, make sure the dial treatment tables are working properly