KX-UT Series
KX-UT133, KX-UT136, KX-UT248 and KX-UT670
Installation Guide CS540 +3.5mm EHS on Panasonic phones
Install a Poly CS540 on a Panasonic KX-DT543
Connect your CS540 with the compatible 3.5 mm EHS cord to hear incoming calls and answer or end them from the headset. The Panasonic handset remains usable. This installation does not require an HL10 handset lifter.
Before you begin
Important: Confirm your phone model and use the Poly 3.5 mm EHS cord specified for compatible Panasonic phones (Poly 84757-01 / HP 85R17AA). Do not connect it to the phone’s separate 2.5 mm headset audio jack. Check the PBX headset/EHS settings if remote control does not work.
Required equipment
| Item | Required equipment or setting |
|---|---|
| Headset system | Poly/Plantronics CS540 base, headset, charging cradle and its supplied power adapter |
| Audio connection | Telephone interface cable supplied with the CS540 |
| Remote call control | Compatible Poly 3.5 mm EHS cord, Poly 84757-01 / HP 85R17AA (separate accessory) |
| Telephone | Panasonic KX-DT543. Verify the exact model on the label beneath the telephone. |
Compatible Panasonic phone models
The 3.5 mm EHS accessory is commonly specified for the Panasonic models below. Verify compatibility of the exact phone, CS540 base and cord before ordering or installing.
KX-DT Series
KX-DT543 and KX-DT546
KX-NT Series
KX-NT543, KX-NT546, KX-NT553, KX-NT556 and KX-NT560
Before ordering: The EHS cord is sold separately. Panasonic system programming can affect ring alerts and remote answer/end functions. Contact us with the telephone and PBX model if you need a compatibility check.
Installation steps
Prepare the phone and base
Leave the Panasonic handset in its cradle. Disconnect the CS540 base power adapter while connecting the cables. Keep the phone connected to its telephone system.
Connect the telephone interface cable
Insert one end in the telephone interface jack on the back of the CS540 base. Disconnect the handset’s coiled cord from the phone and plug it into the interface cable’s junction box. Plug the remaining connector on the interface cable into the phone’s now-open handset jack. Make sure each connector clicks into place.
Connect the Panasonic EHS cord
Plug the compatible Poly 84757-01 / HP 85R17AA cord into the CS540 base’s handset-lifter/EHS jack and the Panasonic phone’s 3.5 mm EHS connection. Follow the connector markings supplied with your cord. Do not use the Panasonic 2.5 mm headset audio jack.
Set the base for the first test
On the underside of the CS540 base, begin with configuration switch A, listening volume 2 and speaking volume 2. These are starting settings; adjust one control at a time during the test call if needed.
Power and charge the headset
Plug the CS540 power adapter into the base and an electrical outlet. Seat the headset in the cradle. The base’s charging LED flashes green during charging and stays solid green when full. Charge for at least 20 minutes before the first test; a full charge takes about 3 hours.
Test remote call control
From another phone, call the Panasonic extension. Confirm that the CS540 alerts you to the incoming call. Press the headset’s call control button once to answer without lifting the handset. Check audio in both directions, then press the button again to end the call. If the call stays active, check the EHS cord and the phone system’s headset/EHS programming.
Daily use
| Action | Headset control | Expected result |
|---|---|---|
| Answer a call | Briefly press Call | The EHS connection takes the phone off-hook and sends audio to the headset. |
| End a call | Briefly press Call | The EHS connection releases the line. |
| Place a call | Press Call, then dial on the phone | Listen for dial tone before dialling. |
| Mute or unmute | Press the volume/mute button inward | Your microphone is muted or restored. |
Troubleshooting
| Problem | What to check |
|---|---|
| No dial tone | Confirm the base has power and the headset is charged and paired. Check the handset interface connections. Start with configuration switch A; test the other positions one at a time if needed. |
| The phone rings, but the headset does not alert | Check that both ends of the Poly 3.5 mm EHS cord are fully seated in the correct ports. Verify the accessory and the Panasonic headset/EHS programming. |
| Call button does not answer or end calls | Confirm that the EHS cord is compatible with both devices and correctly connected. Check phone and PBX headset settings. Test the Panasonic handset to isolate the fault. |
| Caller cannot hear you | Check whether the headset is muted. Bring the microphone close to the corner of your mouth and adjust the base speaking volume one step at a time. |
| Audio is distorted or echoes | Reduce the base’s speaking or listening volume; position 2 is a good initial setting. Test after each change. |
| Static or interference | Move the CS540 base at least 15 cm (6 in) from the phone and 30 cm (12 in) from a computer; test the adapter in a wall outlet. |
Final installation check
- The Panasonic handset still works normally.
- The CS540 alerts you to incoming calls.
- The headset button answers and ends calls without lifting the handset.
- Both callers can hear clearly at a comfortable volume.
- The cables are secure and do not strain their connectors.
Technical note
For this setup, the telephone interface cable carries audio through the Panasonic handset connection and the separate 3.5 mm EHS cord provides remote call control. An HL10 mechanical lifter is an alternative for other setups, but is not used with this EHS installation. Telephone system configuration can vary by site.