XECOM

(5)

XE0017

When developing a product to be connected to the telephone line, it is necessary to use a circuit described as a Data Access

Arrangement (DAA) which is approved by the appropriate governmental agency. In the US, for example, this agency is the Federal

Communications Commission (FCC), while in Canada it is the Department of Communications (DOC). These agencies test and

approve the product to ensure that it meets their specifications, thereby protecting the telephone system from damage and

protecting the user from high voltage transients (such as lightning strikes) which may come down the telephone line.

The XE0017 has been designed to meet all FCC Part 68 requirements for hazardous voltage, surge protection and leakage current.

If the system developed transmits data, or DTMF tones on the telephone line, the user must certify that the signals transmitted meet

basic FCC requirements for maximum transmission levels, out of band energy and billing delay. Full details may be obtained from

the FCC under Part 68 of the FCC Rules and Regulations, or in Title 47 of the Code of Federal Regulations, however the basic

requirements are as follows:

1. Maximum Transmit Level

For the normal “permissive” (standard) telephone line, equipment which transmits data (such as a modem) must not exceed a

transmission level of -9 dBm.

2. Out of Band Energy

Data equipment must not transmit “out of band” energy on the telephone line which exceeds the following limits:

Frequency

Range

Max. Power

200Hz

to

3990Hz

-9 dBm

3990Hz

to

4005Hz

-27 dBm

4005Hz

to

16kHz

-16 dBm

8kHz

to

94kHz

-47 dBm

86kHz

to

270kHz

-46 dBm

270kHz

to

6MHz

-6 dBm

3. DTMF Transmission Level

If the system is capable of DTMF dialing, the maximum DTMF transmission level must be less than 0 dBm averaged over a 3

second interval.

4. Billing Delay

A delay of 2 seconds or greater is required after the time the XE0017 is taken “off hook” and before any information is transmitted.

This is required to ensure that billing information may be exchanged between telephone company central offices without

interference.

The user of the XE0017 must certify to the FCC that the final system meets the requirements of Part 68 which include the criteria

above as well as the high voltage protection provided by the XE0017. This is generally accomplished through an independent

testing lab which tesst the System and submits the proper paperwork to the FCC for approval. Since the XE0017 already comply

FCC Information