3  Functions  Issue 10/06 
  MICROMASTER 440      Operating Instructions 
146  6SE6400-5AW00-0BP0 
NOTE 
¾  A communications (CB) module as well as a programming / operator unit can 
be simultaneously connected to the COM link interface via terminals 29/30 
(USS). This is the reason that the communications module has priority over 
USS. In this case, the USS node (USS station) via the COM link is de-activated. 
¾  Contrary to PROFIBUS, the RS485 port (terminals 29/30) is not optically isolated 
(not floating). When installing the system, it must be ensured that EMC faults do 
not result in communication failures or damage to the RS485 drivers. 
 
3.7.1  Universal serial interface (USS) 
Parameter range:  P2009 – r2037 
Significance  COM link  BOP link 
USS basic setting     
  USS baud rate  P2010[0]  P2010[1] 
 USS address  P2011[0]  P2011[1] 
 USS-PZD length  P2012[0]  P2012[1] 
 USS-PKW length  P2013[0]  P2013[1] 
PZD data     
 Received data  r2018[8]  r2015[8] 
  Received control word 1  r2036  r2032 
  Received control word 2  r2037  r2033 
 Sent data  P2019[8]  P2016[8] 
  Sent status word 1  r0052  r0052 
  Sent status word 2  r0053  r0053 
 
Alarms: --- 
Faults: F0071, F0072 
Function chart number:  FP2500, FP2510, FP2600, FP2610 
Features:  
 
−  electrical features:  Not electrically isolated  USS at the BOP link with PC- 
      converter connecting set 
    Not electrically isolated   USS at COM link  
       (terminals  29 /30) 
 
−  cycle time (MM440): 8 ms  (process data PZD) 
    Background  (parameter ID value PKW)