Справочник Пользователя для IBM LPCI-COM232-8

  
The card supports Half-Duplex communications with a 2-wire cable connection. Half-Duplex allows traffic 
to travel in both directions, but only one way at a time. RS485 communications commonly use the Half-
Duplex mode since they share only a single pair of wires. 
 
 

  
The card has capability for two baud rate ranges and you can select which you wish to use for all ports on 
the card. One range is up to 115,200 baud and the other is up to 921,600 baud. 
 
Note
Refer to Table 5-1, Baud Rate Divisor Values in chapter 5 of the manual. 

  
In RS485 communications, the driver must be enabled and disabled as needed, allowing all cards to 
share a two wire cable. The card controls the driver automatically. With automatic control, the driver is 
enabled when data is ready to be transmitted. 
  
With this card, the driver remains enabled for an adjustable period. It may be disabled at the completion 
of the transmission of the character (default), or can be set to wait up to one additional character's 
transmission time after data transfer is complete and then disabled.  
  
The receiver is, therefore, normally enabled, then disabled during RS485 transmissions, and then re-
enabled after transmission is completed (adjustable from zero to plus one character transmission time). 
The card automatically adjusts it's timing to the baud rate of the data. (NOTE: Thanks to the automatic 
control feature, the card is ideal for use in Windows applications) 

Manual LPCI-COM-8SM 

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