Avaya 8400B Plus Data Service Unit

£70.00 ex. VAT

Get A Quote Ask A Question


The Avaya 8400B Plus Data Service Unit (product code: 8400B) is in stock and available from Office Phone Shop.

The Avaya 8400B Plus Data Service Unit (product code: 8400B) is a full duplex asynchronous data module that provides desktop integrated voice-data communications via twisted-pair wiring.

The 8400B works with the two-wire Definity Digital Communications Protocols Circuits. It replaces (and is compatible with) the 7400B Plus Data Module.

We stock a wide range of new, remanufactured and refurbished office telephone system spares and parts.

Please quote Avaya 8400B Plus Data Service Unit or product code: 8400B when ordering.

Office Phone Shop stock a complete range of Avaya 8XXX Series Business phones & Accessories including:

8434DX IP Phone 

8510 IP Phone 

8410D IP Phone 

8400B Plus DATA service Unit 

26B1 Key Module

Callmaster V 

IP PSU 1151B1

Additional information



Key Features

  • Non-volatile, read-write memory for storing installation options, two data options profiles, and up to four telephone numbers
  • An AT command interface that emulates a Hayes 2400 Smartmodem and supports the following:
  • storage of the wait time for carrier detect interval (S-register S7)
  • voice call origination using the ATDP command
  • Automatic speed and parity adjustment
  • Even, odd, mark, space or no parity
  • Automatic data throughput adjustment
  • Power-up self-test
  • Local and remote loopback tests with test duration timers
  • Voice terminal powered by the PBX is not affected if AC power is removed from the 8400B Plus Data Module

At Office Phone Shop we offer a full one year warranty* on all new, remanufactured and refurbished products.

We offer after sales support** and advice from answering simple user questions to full system programming services. These services are maintained through a combination of online support documents and a full range of business telecoms services, including our maintenance and support services.

We will do all we can to offer our assistance with any problems you may encounter.

Office Phone Shop has built its reputation on offering customer satisfaction. So if you are a customer with a problem, we want to know about it. Our details can be found on the contact page.

*some DECT telephones & untested equipment has a reduced time period warranty.

**where relevant to products/services offered.

UK Delivery

We aim for next day delivery. Any order placed before 1.00 pm on any business day (Monday – Friday excluding Bank Holidays) should be delivered the next business day before 5.30 pm (assuming the item is in stock).

Worldwide Delivery

We ship worldwide from our UK warehouse.

Read more information on Delivery.

  1. The Customer is required to inspect all goods upon receipt and to notify Office Phone Shop of any defects or complaints within 7 days of receiving goods.
  2. It is the responsibility of the customer to ensure the safe return of faulty or incorrect goods to Office Phone Shop.
  3. All goods returned must clearly state customers name, order no, telephone number, fault details and proof of purchasing. These goods must be in Office Phone Shop’s original packaging and condition, with original insertions, fixtures and parts. Failure to do so will result in the refund being invalidated.
  4. We use tamper proof labels which are stuck to each item sold by Office Phone Shop. This ensures that goods have been purchased from Office Phone Shop. When the label is peeled back Office Phone Shop Company details sticks to the glue and the label will then say void. No goods will be accepted back unless this label in intact.