CMU  Connecting the CMU to the Test Setup 
1100.4903.12 1.15  E-10 
Connection via serial 
interface  
 
 
COM 1
 
 
The CMU can be connected to the serial interface of a controller via one of 
the serial interfaces COM 1 or COM 2 and a so-called null-modem cable. 
The pin assignment and wiring of a null-modem cable are described in 
section  Handshake of chapter 8. The technical specifications of the serial 
(RS-232-C) interface are also discussed in chapter 8 (refer to section 
Hardware Interfaces). 
Either a 25-pin or a 9-pin connector can be used on the controller side. It 
may be necessary to use an appropriate adapter (see chapter 8, Hardware 
Interfaces).  
Selection 
 
!  Proceed as described above to activate the Remote tab of the Setup 
menu. 
! In the Port table row, select COM 1 or COM 2 to activate one of the RS-
232 interfaces for data transfer.  
Configuration 
 
 
After selection of a serial interface, the transmission parameters must be set 
to comply with the parameters of the addressed device. This is done in the 
Comm. (communications) tab of the Setup menu: 
 
 
!  To open the Setup – Comm. tab press the SETUP key at the front of the 
instrument and activate the Comm.  hotkey at the lower edge of the 
screen. 
!  In the table section corresponding to the selected COM port check the 
settings for the Baudrate, Data Bits, Parity, and Protocol.