Manual LPCI-COM-8SM
7
Auto-RTS Transceiver Control
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)
Figure 1-1:
Block Diagram (Only one serial channel shown)
