Serial Null Modem

[WestCoastOz]

As an interim measure until the firmware allows EFIS to EMS  switching via the DSAB, I would like to buy a serial null modem as previously recommended on this forum and mentioned in the installation manual.

Is a serial null modem just a gender changer cable/adaptor  ie. D9 male to D9 male ?  as depicted here?
  http://www1.electusdistribution.com.au/productView.asp?ID=1929&CATID=&keywords=d9+male+to+d9+male&SPECIAL=&form=KEYWORD&SUBCATID=

or here:  http://www.expansys.com.au/p.aspx?i=121390&sbadd=121390

or is it something more complex??

Thanks in advance

 

[dynonsupport]

Your second link will work. It is that simple.

Your first link won't. It needs to be called a "null modem." A gender changer moves all pins straight across. A null modem swaps pins 2 &3 as they go across. You need to do this swap.

If you wish to make something yourself, it's really easy. We're actually only trying to get one wire across- pin 3 on the EMS connector to pin 2 on the EFIS connector. If you can do this some other way, with a small jumper or just making your own with some D-9 connectors, you only need to run one wire.

 

[WestCoastOz]

Thanks for the quick response.....I will do as you suggest.