ZOOM TELEPHONICS, INC.
VFD X
| 
 Modem Type  | 
 Data (synchronous/asynchronous)/Fax/Voice  | 
| 
 Maximum Data Rate  | 
 2400bps  | 
| 
 Maximum Fax Rate  | 
 9600bps  | 
| 
 Data Bus  | 
 External  | 
| 
 Fax Class  | 
 Class I & II  | 
| 
 Data Modulation Protocol  | 
 Unidentified  | 
| 
 Fax Modulation Protocol  | 
 Unidentified  | 
| 
 Error Correction/Compression  | 
 MNP5, V.42, V.42bis  | 

| 
 CONNECTIONS  | |||
| 
 Purpose  | 
 Location  | 
 Purpose  | 
 Location  | 
| 
 Line out  | 
 CN1  | 
 DC power  | 
 CN5  | 
| 
 Line in  | 
 CN2  | 
 Speaker  | 
 CN6  | 
| 
 Digital control (Proprietary  | 
 CN3  | 
 Power switch  | 
 SW1  | 
| 
 RS-232/422  | 
 CN4  | ||
| 
 DIAGNOSTIC LED(S)  | |||
| 
 LED  | 
 Color  | 
 Status  | 
 Condition  | 
| 
 VM  | 
 Red  | 
 On/Blinking  | 
 Unread stored messages exist  | 
| 
 VM  | 
 Red  | 
 Off  | 
 No unread stored messages exist  | 
| 
 AA  | 
 Red  | 
 On  | 
 Auto-answer enabled  | 
| 
 AA  | 
 Red  | 
 Off  | 
 Auto-answer disabled  | 
| 
 CD  | 
 Red  | 
 On  | 
 Carrier signal detected  | 
| 
 CD  | 
 Red  | 
 Off  | 
 Carrier signal not detected  | 
| 
 OH  | 
 Red  | 
 On  | 
 Modem is off-hook  | 
| 
 OH  | 
 Red  | 
 Off  | 
 Modem is on-hook  | 
| 
 RD  | 
 Red  | 
 Blinking  | 
 Modem is receiving data  | 
| 
 RD  | 
 Red  | 
 Off  | 
 Modem is not receiving data  | 
| 
 TD  | 
 Red  | 
 Blinking  | 
 Modem is transmitting data  | 
| 
 TD  | 
 Red  | 
 Off  | 
 Modem is not transmitting data  | 
| 
 TR  | 
 Red  | 
 On  | 
 DTR signal is high  | 
| 
 TR  | 
 Red  | 
 Off  | 
 DTR signal is low  | 
| 
 MR  | 
 Red  | 
 On  | 
 Power is on  | 
| 
 MR  | 
 Red  | 
 Off  | 
 Power is off  | 
Proprietary AT Command Set
| 
 AUTO-RETRAIN  | |
| 
 Type:  | 
 Configuration  | 
| 
 Format:  | 
 AT %En  | 
| 
 Example:  | 
 AT %E1 <CR> | 
| 
 Description:  | 
 Selects auto-retrain mode.  | 
| Command | 
 Function  | 
| » %E0 | 
 Auto-retrain disabled.  | 
| %E1 | 
 Auto-retrain enabled.  | 
| 
 BREAK SEND  | |
| 
 Type:  | 
 Configuration  | 
| 
 Format:  | 
 AT [cmds] \Bn [cmds]  | 
| 
 Example:  | 
 AT \B3 &W <CR> | 
| 
 Range:  | 
 1-9  | 
| 
 Default  | 
 3  | 
| 
 Unit:  | 
 .1 second  | 
| 
 Description:  | 
 Sends break to modem.  | 
| 
 COMPRESSION  | |
| 
 Type:  | 
 Configuration  | 
| 
 Format:  | 
 AT %Cn  | 
| 
 Example:  | 
 AT I2 %C1 &S0 <CR> | 
| 
 Description:  | 
 Selects data compression.  | 
| Command | 
 Function  | 
| %C0 | 
 Data compression disabled.  | 
| %C1 | 
 MNP5 enabled.  | 
| %C2 | 
 V.42bis enabled.  | 
| » %C3 | 
 MNP5 and V.42bis enabled.  | 
| 
 CONNECT MODE  | |
| 
 Type:  | 
 Configuration  | 
| 
 Format:  | 
 AT [cmds] \Nn [cmds]  | 
| 
 Example:  | 
 AT \N1 DT555-1212 <CR> | 
| 
 Description:  | 
 Sets connect mode.  | 
| 
 Command  | 
 Function  | 
| \N1 | 
 Direct mode.  | 
| \N0 | 
 Normal mode.  | 
| \N2 | 
 Reliable mode.  | 
| » \N3 | 
 Auto-reliable mode.  | 
| \N4 | 
 V.42 reliable mode.  | 
| \N5 | 
 MNP error correction mode.  | 
| 
 FLOW CONTROL  | |
| 
 Type:  | 
 Configuration  | 
| 
 Format:  | 
 AT [cmds] \Gn [cmds]  | 
| 
 Example:  | 
 AT \G1 &K3 <CR> | 
| 
 Description:  | 
 Selects modem port flow control.  | 
| Command | 
 Function  | 
| » \G0 | 
 Flow control disabled.  | 
| \G1 | 
 Flow control enabled.  | 
| 
 LINE SIGNAL LEVEL  | |
| 
 Type:  | 
 Configuration  | 
| 
 Format:  | 
 AT [cmds] %L [cmds]  | 
| 
 Example:  | 
 AT %L &W <CR> | 
| 
 Unit:  | 
 -dBm  | 
| 
 Description:  | 
 Returns received line signal level.  | 
| 
 LOCK SERIAL PORT  | |
| 
 Type:  | 
 Configuration  | 
| 
 Format:  | 
 AT [cmds] \Jn [cmds]  | 
| 
 Example:  | 
 AT %L3 %B14 \J0<CR>  | 
| 
 Description:  | 
 Sets operation of serial port speed.  | 
| Command | 
 Function  | 
| » \J0 | 
 Serial speed locked.  | 
| \J1 | 
 Serial speed follows connect speed.  | 
| 
 MAXIMUM BLOCK SIZE FOR TRANSMISSION  | |
| 
 Type:  | 
 Configuration  | 
| 
 Format:  | 
 AT [cmds] \An [cmds]  | 
| 
 Example:  | 
 AT \A3 %C1 <CR> | 
| 
 Description:  | 
 Sets the maximum transmittable block size.  | 
| Command | 
 Function  | 
| \A0 | 
 MNP block size is 64 characters.  | 
| » \A1 | 
 MNP block size is 128 characters.  | 
| \A2 | 
 MNP block size is 192 characters.  | 
| \A3 | 
 MNP block size is 256 characters.  | 
| 
 MNP STREAM/BLOCK MODE  | |
| 
 Type:  | 
 Configuration  | 
| 
 Format:  | 
 AT [cmds] \Ln [cmds]  | 
| 
 Example:  | 
 AT \L1 DT555-1212 <CR> | 
| 
 Description:  | 
 Selects the transfer mode for MNP.  | 
| Command | 
 Function  | 
| » \L0 | 
 Stream mode for MNP enabled.  | 
| \L1 | 
 Block mode for MNP enabled.  | 
| 
 REPORT SIGNAL QUALITY  | |
| 
 Type:  | 
 Configuration  | 
| 
 Format:  | 
 AT [cmds] %Q [cmds]  | 
| 
 Example:  | 
 AT %Q &W <CR> | 
| 
 Description:  | 
 Reports signal quality.  | 
| 
 REPORT MODEM STATUS  | |
| 
 Type:  | 
 Immediate  | 
| 
 Format:  | 
 AT [cmds] \S [cmds]  | 
| 
 Example:  | 
 AT \S &W <CR> | 
| 
 Description:  | 
 Displays current modem configuration.  |