Article # 59, added by Geoworks, historical record
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OmniGo Serial flow control




Here is some important information about the OmniGo 100 
serial port's hardware flow control lines. 
 
The only pins connected are 
  Tx (transmit) 
  Rx (receive) 
  RTS (request to send) 
  CTS (clear to send) 
 
The following pins are not connected and can not be used for 
flow control 
  DTR (data terminal ready) 
  DSR (data set ready) 
  RI (ring) 
  CD (carrier detect) 
 
DTR is wired to digitizer, messing with it will blank 
screen. 
DSR is wired to the battery indicator. 
 
On the OmniGo, the built-in serial port is COM 1 and the 
PCMCIA serial port is COM 4. 
 
 
Q. Can I use hardware flow control on the OmniGo? 
 
A. Yes and no.  Yes you can use RTS/CTS, but you cannot use 
DTR. 
 
On the OmniGo, DTR is always high, but when the transceiver 
isn't powered on, the external DTR pin isn't driven.  Since 
the pin is floating, it will most likely appear as neither 
HIGH nor LOW. 
 
 
Q. How do I know if data has been received at a serial port? 
Is there an explicit message sent? or do I have to poll 
using SerialQuery()? 
 
A. You can set up a message for serial event notification.  
See the SDK_C\Serial2 sample application.