Siemens SINAUT ST7 - Page 212

Installing and putting a SINAUT modem into operation
5.5 MD2 dedicated line modem
Station control system
212 System Manual, 07/2009, C79000-G8976-C178-07
Connecting several MD2s with a TIM over the RS-485 port
Several MD2 modems can be connected to a TIM over the RS-485 port. This type of
configuration is necessary when several dedicated lines come together on one TIM; in other
words when connecting a star network. The following figure shows this configuration with
standard components.
/723
/723
/723
7,0
0'0'
0'
&RQQHFWLQJFDEOH
1+'/
&RQQHFWLQJFDEOH
1+$5
&RQQHFWLQJFDEOH
1+$5
&RQQHFWLQJFDEOH
1+$5
56
56
56
$FWLYDWH
WKH
WHUPLQDWLQJ
UHVLVWRURQ
WKHODVW
FRQQHFWRU
2YHUYROWDJHSURWHFWLRQ
/7231+%&
RU
/7231+%&
ZLUH
'HGLFDWHGOLQH
SDWK
ZLUH
'HGLFDWHGOLQH
SDWK
ZLUH
'HGLFDWHGOLQH
ZLUH
'HGLFDWHGOLQH
Figure 5-18 Connecting several MD2s to one TIM over RS-485, star-shaped convergence of several
dedicated lines
For the connection from the TIM to the first MD2, the 6NH7701-4DL standard connecting
cable is used. For the connection to the other modems, there is no preassembled connecting
cable available. These can, nevertheless, be implemented with the standard components
from the S7 range. The same parts can be used as when creating an MPI connection. As
cable, we recommend 6XV1830-0AH10, and as connector 6ES7972-0BA12-0XA0. When
necessary, the RS-485 terminating resistor can be activated in this connector.