Communications configuring 
 
3-144  System- and communication configuring D7-SYS - SIMADYN D 
  Edition 12.2003 
"slower broadcast transmitter" is not blocked by a "faster" broadcast 
transmitter. 
The USS master coupling monitors the delay time of the received 
telegram. The time interval between the last character of the transmitted 
telegram and the first character of the received telegram is considered to 
be the delay time. The maximum permissible delay time is 20 ms. If the 
addressed slave does not respond within the maximum permissible delay 
time, the USS master coupling flags the receive channel, assigned to this 
slave, as being faulted. If a receive channel is not configured, no error 
entry is made. 
The USS master coupling then transmits a telegram destined for the next 
slave. 
The error entry for the faulted slave is only reset after the slave receives 
the next error-free telegram. 
3.13.6  USS master on the T400 technology module 
This section describes the special issues which you have to observe 
when using the USS master coupling on the T400 technology module.  
In this section, 
you will only find the differences over to Section 13.1 
to 13.5
. 
The USS master coupling allows you to connect, approx. 
−  17 drive converters or 
− 
19 OP2 operator control devices, or 
− 
8 drive converters and 8 OP2 
As prerequisite for the coupling, you will require a 
T400 technology 
module (terminals 70..71, serial interface X01 or terminals 74..75, serial 
interface X02)
. 
Data transfer uses a half-duplex technique according to the RS485 
Standard via a 2-conductor cable. 
•  It is not possible to simultaneously use two USS couplings  
(USS master, USS slave) on the serial X01 and X02 interface. 
•  You must set switch S1/8 to the on position so that you can use the 
serial X01 interface
 for the USS master coupling. 
3.13.6.1  Basis network for the T400 technology module 
You must set the switch according to the table below dependent on 
whether you are using the T400 technology module as 
end node or not 
as end node
 on the USS bus, i.e. at the end or not at the end of the bus 
cable. 
Monitoring 
mechanisms and 
error response 
Please 
note: