ZyXEL Communications omni series user manual Isdn Communication Basics, Understanding AT Commands

5 ISDN Communication Basics

In this chapter, we will cover how to initiate and receive calls over digital lines using your TA.

Understanding AT Commands

AT commands are used to configure and control the omni. Command statements are usually sent to the TA by being typed from the computer keyboard.

Command statements must be written in a specific form in order for the TA to recognize them. A command statement begins with the letters “AT” or “at”. It is then followed by one or more commands and then by <Enter>.

AT commands can only be issued when the TA is in “command” or “off-line” mode.

Once the TA has established a connection with the remote device, it goes into “on-line” mode, and the characters sent from your computer (through the TA) are transmitted to the remote device.

In order to issue an AT command statement, you first need to run your communications software and configure it to the port connected to the TA. Refer to your communications software manual if this is not the case.

Once the communication terminal program is running and the TA is connected:

Type:

AT<Enter>

TA responds:

OK

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