Features and Specs
- Digital; Ethernet IP 10/100 Network
- 30 (up to 150) Programmable Keys
- Dedicated Voicemail Key
- Dedicated Help Key
- Dedicated Record Key
- Full Duplex Speakerphone
- Integrated Headphone Jack
- Power Over Ethernet
- Busy Lamp Field (BLF)
- Call Forward
- Call Transfer
- Conference
- Do Not Disturb / Mute
- Redial
- 3-line, 56-character Adjustable Backlit Display
ESI 55 USER GUIDE
Special Keys and Their Uses
Lets you drop a call without replacing the handset.
Press to place a caller on hold for pick up at any station. To pick up a held call, press HOLD. The display will show which outside lines are holding calls, with the most recently held calls on the right. Enter the appropriate line number — for example, 1 2 for line 12 — to pick up the call.
To place a caller on exclusive hold — i.e., for pick up only at your station — press HOLD for at least one second. The display will show an “E” next to the outside line where the call is on hold just for your station.
Press SPEAKER for hands-free conversation.
During a conversation, press RECORD to toggle (turn on/off) live recording.
While on a call, press CONF and call someone else to add them to a conference call among up to the maximum number of people (counting you) that your ESI phone system allows in a conference.
During a conversation, press MUTE/DND to disable your microphone. When your station is idle, press MUTE/DND to toggle (turn on/off) do-not-disturb mode.
Lets you transfer a call to a station for which you don’t have a programmed station key. Press TRANSFER and then dial the extension number.
Press FLASH to generate a flash hook on the outside line or to toggle between calls waiting.
Press REDIAL to redial the last outside number dialed. If you have Caller ID service, press REDIAL while listening to a voice mail message to automatically return the call.
A call ringing at another station or group can be answered from your station by pressing P/UP, then the appropriate blinking station key or entering the extension number (e.g., P/UP 1-0-3 to pick up a call on extension 103).
To page through all available stations, press PAGE 0.
To page in only a programmed paging zone, press PAGE and the one-digit paging zone designation (in a range of either 1-3 or 1-9, depending upon your system; see the System Administrator for assistance).
Using Your Phone
Answering a call
When your phone rings, lift handset or press SPEAKER. If your station is set for hands-free answer, intercom calls will be automatically output to your speaker.
Placing an outside call
Lift the handset, press an unlit line key or dial 9 (or 8 or 7) to be assigned outside dial tone; or, without lifting the handset, dial 9 (or 8 or 7) to be automatically connected to outside dial tone through your speaker. Placing an intercom call Lift the handset and press a station key or dial the extension number; or, without lifting the handset, press a station key to call the station through your speaker.
Placing an Intercom call
Lift the handset and press a station key or dial the extension number; or, without lifting the handset, press a station key to call the station through your speaker. The station LEDs indicate:
Speed-dialing with Esi-Dex
You can select and auto-dial from three speed-dialing lists (or Dexes): the System Dex; the Station User’s Dex; the Location Dex (if you’re using Esi-Link); and a Personal Dex of names and numbers you have either entered via keypad or captured via Caller ID. (This data may also have been programmed by your Installer or system Administrator.)
Press ESI-DEX (while your station is idle) and choose the appropriate Dex from the display. Use the volume/scroll keys (and) to find the desired name. When it appears, select DIAL.
Transferring a call to another station
While connected to an outside caller, press the unlit station key for the person to receive the call (or press TRANSFER and dial the extension number). To perform an unsupervised transfer, hang up immediately. For a supervised transfer, wait until the called person answers, announce the call, then hang up. If, during a supervised transfer, the transferred-to person doesn’t answer, press the station key again or press FLASH/RDL to return to the original caller; or hang up to release the call to the station’s mailbox.
If you call or transfer a call to a station in use (the station key is solid red), the called person can handle your call as outlined in the call waiting feature (see next column) — or decide not to take your call, in which case it will forward to his/her mailbox.
Transferring a call directly to mailbox
To transfer an outside call to another user’s mailbox, press VOICE MAIL and then TRANSFER, and then dial the extension number. Even though you both will hear the personal greeting, you can hang up at any time to release the call to the mailbox.
Transferring a call to the main menu
To transfer an outside call to the main menu, press VOICE MAIL and hang up.
Leaving a message in another user’s mailbox
Press VOICE MAIL and then TRANSFER, and then dial the extension number. If you press 1 during the user’s personal greeting, you will advance directly to the record tone.
To leave a message in several mailboxes (Quick Groups), press VOICE MAIL and the appropriate station keys prior to the record tone.
Initiating a conference call
While connected to a call, press CONF, call another station or outside person, and then press CONF again. Repeat this procedure to add another person (up to the maximum, including you, that your ESI system allows) to the conference. Hang up to disconnect all persons in the conference. If the newest added-on person does not answer, press his/her station key again or press FLASH/RDL to return to the original conferees.
Picking up a call at another station
If a call is ringing at another station (if it’s programmed into one of your station keys, that key will be blinking red), that call can be picked up at your station by pressing P/UP, then either pressing the ringing station key or entering the extension number (e.g., P/UP 1-0-3 to pick up a call on extension 103).
Call waiting
If you receive another call while you’re already on a call and you have activated call waiting (see “Programming your phone,” elsewhere in this guide), you will hear a tone in your earpiece and the second line of your display will indicate that a call is waiting. You can ignore the call waiting (and it will be directed to your mailbox), or you can toggle between the two callers by pressing FLASH/RDL. To drop either call, press RELEASE and you will be automatically connected to the other call (or hang up while connected to the call to be dropped and your phone will then ring with the other call).
Dialing 911
Dialing 911 from a local phone (i.e., not from a remotely installed IP phone) places an emergency call and also notifies the system operator via a spoken and displayed prompt.
Programming Your Phone
Setting your phone preferences
Press PROG/HELP to access programming, and then select from the menu choices. During any programming step, you can press PROG/HELP for a detailed description of the feature.
0 — Help
- 1 • How to use the phone
- 2 • How to use voice mail
- 3 • Phone features
- 4 • User tutorial
1 — Select personal greeting
- 1 • Record
- 2 • Delete
- 3 • Hear
2 — Programmable feature keys
3 — Station options
- 1 • Call waiting
- 2 • Personal greeting reminder
- 4 • Dial tone preference
- 5 • Hands-free answer
- 6 • Monitor mode
4 — Station audibles
- 1 • Station ring tone
- 2 • Station ring volume
- 3 • Message ring
5 — Password
- 1 • Enter
- 2 • Delete
- 3 • Hear
- 4 • Security level
6 — External notification
7 — Personal Call Routing
9 — Message Recycle Bin
Programmable Feature Keys
There are two methods for programming your phone:
- Direct programming — Select the key you want to program, and hold it down for at least two seconds. This not only initiates programming but also lets you immediately program that specific key.
- Traditional programming — Press PROG/HELP. The Verbal User Guide will speak to you, walking you through the full menu, during which you can choose the appropriate option.
The programmable feature keys can be programmed as:
- Line keys — If programmed with a two-digit line number, the key will become a line key providing lamp information and outside line access.
- Station keys — If programmed with a three- or four-digit extension number, the key will provide station lamp status and direct station access and transfer.
- Speed-dial keys — Can be used for automatic dialing of frequently called outside numbers. Enter the line access code (9, 8, or 7) plus the phone number.
- Additional-feature keys — Depending on your system, these may include day/night control, service observing, agent log-on, system speed dial, personal greeting, etc. See the System Administrator for assistance.
Special Features
Monitor mode
You can program your phone to allow hearing a message as it is being left in your mailbox, for your selective interception.
Call forwarding
Press CFWD and then press a station key (or enter an extension) to forward your call to that station. To disable call forwarding, dial CFWD ✱ and hang up.
Message Recycle Bin (un-delete)
Your phone system stores your 10 most recently deleted messages in a Message Recycle Bin (PROG/HELP 9) to allow you to recover messages that may have been deleted in error.
Off-hook indicator/message light
The red message light, located at the right corner of the phone, indicates three conditions. A phone that’s off-hook glows solid red (first priority), continuously “flutters” when ringing (second priority) and blinks when that station has new voice mail waiting (third priority). The indicator will light according to the priority of the condition.
Headset jack
Your phone is equipped with a headset jack (located on the bottom of the phone). To use a headset, first assign 5-6-4 to a programmable feature key, making it a headset key; then plug the headset into the phone. To answer a call, press the headset key you programmed (to release the call, press the headset key again). You can still use the handset at any time; however, to switch back to headset mode, you must press the programmed headset key before placing the handset back in its cradle.
Using Help Mode
Your phone’s help mode is designed to help you learn about phone features, how to use your phone, how to use voice mail, and how to handle calls and messages (user tutorial). To access one of these topics, press PROG/HELP and choose from the menu.
While programming a feature on your phone, you can press PROG/HELP to hear a more detailed description of that feature.
The on-board user tutorial — PROG/HELP 0 — explains all aspects of call and message handling in a logical, step-by-step manner.
Using Voicemail
If you have new messages, your display will show the number of new and old messages in your mailbox.
Retrieving messages from your station
- Press VOICE MAIL.
- When prompted, enter your password (if required) plus #. The default password is 0 (meaning, no password required).
During playback of a message, the display will show the originator of the message, the duration of the message, whether it’s new or old, and the time/date of the message.
You can press any of the following keys anytime during the message or during the prompt following the message.
Pause — Pauses playback for one minute or until pressed again.
Time/date to number — Toggles the upper display between the time/date and the Caller ID number (if available).
Reply — To automatically reply to a message from another user (within the system). Begin recording your reply at the tone; press 1 to stop. You will then be returned to the original message for further action.
Rewind — Rewinds playback four seconds for each time you press it during message playback. If pressed after the message has finished, returns you to the message’s beginning.
Fast forward — Advances playback four seconds each time you press it.
Copy — Copies a copy of the message to another user’s mailbox or to a Quick Group. If you wish to add an introduction, press 1 when prompted. The phone system will respond with the mailbox greeting and record tone. When you’ve finished your recording, press 1 to stop.
Delete — Deletes the message.
Save — Saves the message. It will be played as an old message the next time messages are retrieved. Note: 9 9 saves the message as a new message.
Hang up when finished. (If you hang up while a message is playing back, the message will remain a “new” message.)
Retrieving messages from a remote location
- At the main greeting, either press ✱ and enter your mailbox number, or have the operator transfer you by pressing VOICE MAIL and then ✱, and entering your mailbox number.
- When prompted, enter your password (if required) plus #. The default password is 0 (meaning, no password required).
The phone system will announce the number of new and old messages and play the oldest new message.
The additional key functions listed below may be used from a remote location:
Hear time/date — Pauses the message, plays the time/date of the message and then resumes playback.
Access user programming — Lets you change the personal greeting or password. Note: Fast forward is not available from a remote location.
Main greeting — Returns you to the main greeting.
Operator — Transfers you to the operator.
Leave a message In another mailbox — When prompted, enter the user’s mailbox number.
To disconnect — Use before hanging up (if pressed during playback of a message, the message will be saved).
Mailbox personal greetings
You can record up to three personal greetings (PROG/HELP 1), and then change between them as desired.
Example: “Hi, this is Bill. I’m away from my desk or on the phone. You may reach the operator by dialing 0 now; or leave me a detailed message and I’ll respond to it promptly.”
If you have any questions not covered within this guide, please contact us for assistance.
Compatible Systems

ESI IP Server 900
ESI IP Server 900 is a unified communications system combining the reliability of an on-premises phone system with the flexibility of network connectivity.

ESI Communications Servers
ESI Communications Servers give you the flexibility of both digital functionality and IP-to-the-desktop in any combination.