Null Modem Question

[bz1801]

I am new to this stuff, so please bear with me. I am working with a Siemens 840C control that has a 25 pin port on it. I have a 9 pin to 25 pin cable to hook up to my laptop. I've used this same laptop to transfer programs to a Mazatrol control, but I have to use an adapter with the cable. The adapter says "Null Modem (full handshake)" on it and has a pin diagram. It is 25 pin male-female.

In my research about the Siemens control, I found some pin diagrams that say "Null modem cable, with/without full handshake, etc." What I'm assuming is that the adapter I have is exclusive to the Mazatrol control, and that I'll have to get a different one for the Siemens. This leads me to my second question: How do I obtain a null modem adapter or cable that has the correct pin configuration on it? Is this something I can purchase or do I have to make it? Or, is this a standardized thing across the board? Any info would be great, since the more information I'm finding on my own is just confusing me more.

[Al_The_Man]

I think the adaptor you have takes a 'straight through' type cable and set the pins for null modem use together with hardware handshake signals,
You will need a null modem cable for the Siemens so the adaptor should work.
This link explains the conections a bit more in detail.
http://www.cadem.com/ncnet/dnc-detai...merik-802d.pdf
With full handshake usually all the handshake connections are made across the cable, with no handshake they are usually jumpered out inside the connector.
Al.

[Dan Fritz]

Al_The_Man is right. The null modem adapter you use with the Mazatrol should work on the Siemens too.

[bz1801]

I tried it and it does work with the Siemens. Thanks for the info.