Opening Up A PolyCom Soundstation EX

That Polycom runs off of Analog dial tone.
Either a dedicated line or in most cases from an ATA off the phone system.
You should be calling your vendor/tech in that handles the phone system to check programming, cabel, jack and the Polycom itself too.

No it can't. One call at least must be dialed out to. Try using a conference bridge service if you want to have multiple parties call in to you. Then you and all guests only need to call bridge number which is usually toll free.

What system is the phone on?

It depends on what system it is installed on.

NUT, generally, with the first caller on, press flash you will get intercom tone again, dial 9 and connect to the next party. Once connected, press flash again and you should be connected to the original party.

repeat you setup for all station you want to connect to it.

Check the phone cable you are using for your POTS line. Attach a phone directly to the phone jack and see if it is clear or static without the device.

change the battery

How can I add 3 other people on the conference call using a Polycom Soundstation?

The conferencing capability to bridge 2 (or more) external stations comes from the telephone equipment/service that you have purchased. Either you are behind a PABX or Electronic KSU, which provides multiple phone service to your office, or you purchase conferencing capability from your local telephone provider (Verizon, AT&T, etc). In either case, the way to initiate a conference call would be the same as when you would have a desktop/office phone and establish a conference/bridged call to external parties. Usually this occurs by having one party on the line, flashing the disconnect button momentarily, getting a new dial tone, dialing and connecting to a second party, then flashing the disconnect button again, which signals the equipment to bridge those two calls to your station.  On the SoundStation EX there is a Flash button that provides that capability of momentarily flashing the disconnect button.  Try and see if that works. If not, then you will need to make arrangements to purchase the external equipment or service from your provider.  If you have the PABX or electronic KSU, it may also be a configuration option that you will need to have your support person for your telephone system, activate for that station connected to the SoundStation EX. Hope that helps. 

Someone in our office recently damaged the RJ-45 cable for our Polycom Soundstation. Because the jack was damaged I could not determine the order of the cables. After a call to polycom, we found the pinout information we needed - so I thought I would share, in case anyone else finds themselves in a similar situation:
With the RJ-45 prong pointing down the wires, from left to right are:

• Black
• Brown
• Red
• Orange
• Yellow
• Green
• Blue
• White

Then Crimp and test. I got this information directly from Polycom for use with the Polycom Soundstation. This information was not easy to get. They originally told me they could not provide the information and I would have to buy a power adapter. This is not true, just trim the cable and follow the above instructions.