Communications configuring 
 
3-146  System- and communication configuring D7-SYS - SIMADYN D 
  Edition 12.2003 
3.14  USS slave coupling 
The USS slave coupling allows you to  
−  transfer process data 
−  handle and visualize parameters 
To exchange process data, you have a maximum of 
−  one transmit channel (actual values) and  
−  one receive channel (setpoint). 
You can transfer up to 32 process data sets, each 16 bits via each of 
these channels.  
For the coupling, you require a 
T400 technology board (terminals 70..71, 
serial interface X01 or terminals 74..75, serial interface X02)
. 
Data transfer is realized using a half-duplex technique via a two-
conductor cable in accordance with the RS485 Standard. 
 
•  It is not possible to simultaneously use two USS couplings (USS 
master, USS slave) at serial interfaces X01 and X02. 
•  You must switch-in switch S1/8 (close) so that you can use serial 
interface X01
 for the USS slave coupling. 
 
3.14.1  Basis network for the T400 technology module 
Depending on whether you use the T400 technology board 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, then you must 
open or close the switches according to the 
table below
. 
Serial interface  Switches 
X01  S1/1 and S1/2 
X02  S1/3 and S1/4 
 
3.14.2 Initialization 
You must configure the function block @USS_S so that you can initialize 
the USS slave bus coupling . 
 
Please note the 
following: