Technical data

Glossary
TeleService V6.1 Service Software for SIMATIC S7 and C7
Glossary-2 A5E00921336-01
D Channel Protocol
D channel protocols are used for ISDN network services. The ISDN network point
and the ISDN adapter connected to it have to use the same protocol.
Various D channel protocols are available:
• For example, the protocols DSS1 and 1TR6 are used in Europe
• For example, the protocols NI1, 5ESS and DMS100 are used in North
America.
• You can set the corresponding D channel protocol in the "Internal ISDN-TA"
dialog box.
Data Flow Control
During the course of a connection the data flow has to be stopped briefly if, for
example, the modem buffer is full. There are two possibilities for controlling the
data flow:
• Software protocol XON/XOFF
• Hardware protocol RTS/CTS
In the software protocol one of the connected devices sends an XOFF control
character when it is no longer possible able to take up further data. The sending
device then waits with the transfer until the receiving device sends an XON control
character.
In the hardware protocol RTS and CTS are changed over at the serial interface in
order to interrupt the signals of the RS232 control cables.
As a rule both the modem-to-modem flow control and the end-device-to-end-device
flow control can be set with the Hayes command set.
DCD
Data Carrier Detect: RS232 interface circuit which becomes active (ON) when a
remote connection is established.
DCE
Data Carrier Equipment: Data circuit-terminating equipment: Modem
Dialing Method
Set the dialing method (tone or pulse dialing) common for your phone connection.
During pulse dialing you hear crackling noises. During tone dialing you hear noises
with varying tone heights.