Computer DB9 Connections

[Nallin]

Hey there.
In order to mantain the DB9 connector from EFIS and the DB9 connector from EMS avaible to laptop connection we want to jump de wire from pin 2 (EFIS) direct to wire from pin 3 (EMS). Will be there some problems in data transfer?

 

[dynonsupport]

The easiest way to criss-cross pins 2 and 3 is with a serial null modem. They're only a few dollars from radio shack. The, when you want to hook up to a laptop for firmware upgrades, you just pull the null modem out and you have direct access to both PC connectors.

 

[Nallin]

I need to know if the EFIS wire 10-DB25 ( wire 2-DB9 ) is jumped ( not by connectors and yes by jumping the wires ) in the EMS wire 12-DB37 ( wire 3-DB-9 ) , will I have problems while the notebook transmit or receive to/from EFIS/EMS ?

 

[dynonsupport]

Yes, you will have problems. You must be able to disconnect this jumper during an update from the PC.