User`s manual

&T3 Remote Terminal (RT) S16
&T4 * Enable Remote Loopback (RL) S23
&T5 Disable Remote Loopback (RL) S23
&T6 Remote Loopback S16
&T7 Remote Loopback with Test Pattern S16
&T8 Local Loopback with Test Pattern S16
&T9 Test Pattern S16
&X0 • Internal timing S27
&X2 • Slave timing S27
AT Attention characters
Every command line must begin with the attention characters “AT” and end with a carriage return (Hex 0D). The “AT”
command string must be less than 30 characters.
D Dial command
The D command instructs the CSU/DSU to pulse dial a telephone number. The DSU must be in switched mode (&L0) in
order to dial. The format for the dial command is “ATD n” where n is the telephone number to dial including any dial
modifiers. After a number has been dialed call progression responses (CONNECT, NO ANSWER, etc.) will be sent to the
DTE.
H Hang-up command
Sending an ATH command causes the switched 56k call to terminate.
I Returns CSU/DSU information
This command returns information (in the form of an ASCII string) from the DSU/CSU followed by a valid command
response.
I or I0 Display product code
I1 Display ROM checksum
I2 Display Firmware Revision Level
O This command returns the CSU/DSU to data mode if DTR control is configured for &D1 or &D2
Sr? Read register number r
This command reads the decimal value of register r.
ATS0? reads the current value of register 0. A three character decimal number is returned (for example, 000, 014, 255)
followed by a valid command response.
Sr=n Store value n into register r
This command stores the decimal value n into register r.
ATS0=1 stores 1 into register 0.
V Response format
This command instructs the DSU whether to respond to commands with words or numbers. The responses are described in
Appendix D on Page 43.
V or V0 DSU sends numeric responses
V1 DSU sends word responses
&C DCD control
This command configures the DCD options
&C or &C0 Forces DCD on permanently
&C1 Normal DCD operation - DCD is on unless CSU is receiving control codes (powerup default)
&C2 Normal DCD operation - CTS is turned off if DCD is off