Technical specifications   
A.11 S7-200 SMART cables 
  S7-200 SMART 
782  System Manual, V2.3, 07/2017, A5E03822230-AF 
Use the RS-232/PPI Multi-Master Cable for Freeport operation 
For connection directly to your personal computer: 
●  Set the PPI/Freeport mode (Switch 5=0) 
●  Set the baud rate (Switches 1, 2, and 3) 
●  Set Local (Switch 6=0). The Local setting is the same as setting the PC/PPI cable to 
DCE. 
●  Set the Protocol select to 10 Bit (Switch 7=1). See Note below. 
For connection to a modem: 
●  Set the PPI/Freeport mode (Switch 5=0) 
●  Set the baud rate (Switches 1, 2, and 3) 
●  Set Remote (Switch 6=1). The Remote setting is the same as setting the PC/PPI cable to 
DTE. 
●  Set the Protocol select to 10 Bit (Switch 7 = 1). See Note below. 
 
PUs require the protocol select switch 7 to be set to 1 to allow Freeport mode. 
Setting switch 7 to 0 disables Freeport mode in the CRxxs CPUs.
 
The SR and ST CPUs ignore the select switch 7 setting.