Helmholz Modem 56k small, Operating Manual

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Helmholz Modem 56k small/Modem 56k USB small 87
14.2 PC Interface
14.2.1 Serial interface
(Only for HELMHOLZ Modem 56k small )
Layout of the 9-pin D-SUB jack
Description of the signals on the 9-pin D-SUB connector on DCE side:
9-pin D-
Sub DCE
Pin No.
Description
AT com-
mand
Function
CCITT
V-24
EIA
RS23
2
DIN
66020
E/A DCE
to DTE
1 DCD AT&C Data Carrier Detect 109 CF M5 O
2 RXD Receive Data 104 BB D2 O
3 TXD Transmit Data 103 BA D1 I
4 DTR AT&D
Data Terminal
Ready
108 CD S1 I
5 GND Ground 102 AB E2
6 DSR AT&S Data set ready 107 CC M1 O
7 RTS AT&R Request to send 105 CA S2 I
8 CTS AT&K Clear to send 106 CB M2 O
9 RI Ring Indication 125 CE M3 O
14.2.2 USB Interface
(Only for HELMHOLZ Modem 56k USB small)
Layout of the 4-pin USB jack, type B
Description of the signals:
Pin Name
1 USBVCC, USB supply voltage
2 D-, data line
3 D-, data line
4 GND, ground